“Suppose scientists announced today that scientists discovered that all human behavior is entirely caused by previous events. This would mean that whenever a person acts, that action is completely caused by events that occurred earlier in a person’s life, and those events are also completely caused by even earlier events eventually going back to events that occurred before a person was born. This also implies that events that occur before a person is born are part of a sequence that will definitely cause all the actions and decisions that person makes. Now imagine that John decides to cheat on his taxes and does it. If the scientists are right, then John’s decision to cheat on his taxes is completely caused by a series of events that started before he was born. So, the question is: Did John decide to cheat on his taxes freely? Is John morally responsible for cheating on his taxes?”

Imagine you found out you have no free will—you’re something like a robot or a hologram, and all your actions are precisely scripted and dictated by your programming. Would this knowledge change how you live your life or what you value? Should it change the way you treat other people or the way you feel about your successes or failures? Some people spend virtually their entire professional careers thinking about these and related issues. Many theorists argue that beliefs about free will are essentially related to our conceptions of ourselves and our relationships with others. These conceptions and beliefs in free will run deep and are thought by some to underwrite our notions of justice, punishment, desert, and self-worth (Kane, 1996). There is gathering experimental evidence that perhaps these views are at least in part correct where decreasing belief in free will can be related to increases in cheating behaviors (Vohs & Schooler, 2008) and worse job performance (Baumeister, Masicampo, & DeWall, 2009; Baumeister, Sparks, Stillman, & Vohs, 2008; Stillman, Baumeister, & Mele, 2011).Footnote 1 Some think that these connections run so deep that if we are in fact not free or morally responsible, we should allow people to continue to have a false belief about their freedom and moral responsibility (Smilansky, 2000). If these theorists are right, then our understanding of what is required for freedom and responsibility forms a cornerstone of our understanding of ourselves and our relation to the world.

In this chapter, we provide an overview of some of the classic findings in the experimental philosophy of free will. These classic findings suggest that people’s intuitions about freedom and moral responsibility are at least sometimes related to a variety of factors including the affective content of the scenarios and how determinism is described. However, we focus primarily on results from our research program indicating that in a wide variety of instances, people’s free will and moral responsibility intuitions are associated with general and heritable personality traits. In later chapters, we will argue that the relation between personality and free will and moral responsibility challenges some long-standing assumptions held both by traditional and experimental philosophers.

The Experimental Philosophy of Free Will

It is common for philosophers to take intuitions that are pervasive among non-professional philosophers seriously. The intuitions of philosophical non-experts are sometimes referred to as “folk intuitions.” There is some debate about what intuitions actually are, but they are generally thought to be immediate reactions or judgments that one has about concrete situations or scenarios (see, for more details, A. Feltz and Bishop (2010) and Chap. 6). Some have argued that positions supported by folk intuitions have “squatter’s rights” (Dennett, 1984; Nahmias, Morris, Nadelhoffer, & Turner, 2006b). That is, those who endorse philosophical views that are inconsistent with folk intuitions shoulder an additional argumentative burden to explain why those intuitions are mistaken. Those who have views consistent with folk intuitions do not shoulder an additional argumentative burden. Of course, a theory need not respect folk intuitions about freedom and moral responsibility. For example, those who have views about free will and moral responsibility that are inconsistent with folk intuitions could offer a revisionary account of free will and moral responsibility (Vargas, 2005). But even in revisionary views, leading authorities agree that some account of folk intuitions is desirable. Precedent entails that if folk intuitions about freedom and moral responsibility play this role (e.g., determining squatter’s rights), then they can have some substantial role to play in philosophical theorizing about free will and moral responsibility. The same way a representative in Congress would ideally want to proxy the interests and intent of their constituents, so too should the ethicist, philosopher, and legal scholar somehow represent the folk in their analysis.

Often philosophers, bioethicists, legal scholars, and others make an explicit and direct appeal to folk intuitions about freedom and moral responsibility to support their views (e.g., Beauchamp and Childress (2009); Dennett (1984); Kane (1996); Pink (2004); Sommers (2010); Strawson (1986)). Most adults make free will and moral responsibility attributions and judgments routinely and without much difficulty. This everyday practice is of primary interest of scholars and philosophers of free will—it is the phenomenon that many philosophers are interested in understanding, analyzing, and theorizing about. Theories of free will and moral responsibility that are not constrained by everyday practices run the risk of being “philosophical fictions,” (Mele, 2001)—views that may be internally consistent but do not refer to anything in the real world or of value to people. Some scholars who think that philosophical theorizing about freedom and moral responsibility should be constrained by folk intuitions assume that they have a fairly good understanding of everyday attitudes about freedom and moral responsibility. For example, talking in general terms about intuitions, Jackson writes “it is also true that [professional philosophers] often know that our own case is typical and so can generalize from it to others” (1998, p. 37).

As noted in the introduction, a growing body of research indicates that making reference to folk intuitions to support philosophical claims about free will is more tenuous and complicated than might have been thought. One obvious sign of the difficulty is that sometimes theorists disagree about what everyday intuitions about freedom and moral responsibility are. For example, some think that everyday intuitions are compatibilists (i.e., free will is compatible with the truth of determinism) whereas others think that everyday intuitions are incompatibilist (i.e., free will is not compatible with the truth of determinism) (Dennett, 1984; Ekstrom, 2002; Kane, 1996; Lycan, 2004; Pink, 2004; Strawson, 1986; Wolf, 1990). On the face of it, not all these views are accurate descriptions of folk intuitions—folk intuitions cannot primarily support compatibilism and incompatibilism. Determining which views best describe what intuitions people in fact have about freedom and responsibility is efficiently done using empirical methods of the behavioral sciences—an approach that has been dubbed “experimental philosophy.”

The scenario at the start of this chapter is a research instrument designed to represent key elements of determinism. Determinism is the thesis that “at any instant exactly one future is compatible with the state of the universe at that instant and the laws of nature” (Mele, 2006, p. 3). The question of whether John is free and morally responsible is known as the compatibility question—a fundamental question that has taken center stage in the contemporary free will debate (Kane, 1996; Sommers, 2010). Compatibilists think that the answer to the compatibility question is “yes” because they hold that free will and moral responsibility are compatible with determinism. Incompatibilists think the answer is “no,” John is not free or morally responsible. Theorists predictably disagree. On the one hand, some think that John is not morally responsible because his decision to cheat on his taxes was completely caused by a series of events that extends back in time to before he even was born. And, the thinking goes, John cannot be morally responsible for or freely do things that happened before he even existed. So, he cannot be responsible for anything that is completely the result of those events (Strawson, 1994; Van Inwagen, 1983). Given the past and the laws of nature, there is nothing John could have done not to cheat on his taxes. On the other hand, John is a complex individual who makes decisions based on his particular set of desires and beliefs. Even if those desires and beliefs were completely determined by other factors, he was not coerced or forced into cheating on his taxes—his cheating on his taxes is an expression of who he is and what he values (Frankfurt, 1971; Watson, 1975). So, for these reasons, one might think that John acted freely and is morally responsible for cheating on his taxes.

Some of the early empirical work suggested that everyday intuitions supported compatibilism. But asking for people’s intuitions about determinism’s relation to freedom and moral responsibility is no easy feat. Determinism is a technical term that not many people completely understand the way that philosophers do. Because of the challenges associated with describing technical philosophical concepts, researchers often use scenarios that capture central elements of those concepts. These scenarios can convey some of the key elements of determinism to non-experts without having to use technical jargon. To illustrate, Nahmias, Morris, Nadelhoffer, and Turner (2005) presented participants with several scenarios describing a person acting in a deterministic universe. Almost no one thinks that determinism actually describes the causal processes of our world (see Nichols and Knobe’s study below). So, Nahmias and colleagues described a hypothetical supercomputer that knows all the laws of nature and has a complete description of the universe at a given time. From these facts, the supercomputer infallibly deduces everything that will happen in the future. In a determined world, nothing is in principle unpredictable, so the supercomputer is meant to illustrate a central element of determinism. They then asked participants if the person freely performs and is morally responsible for an action in that world. One of their studies involved a person named John who robs a bank.Footnote 2 The supercomputer predicts that John will rob a bank at a precise date and time, and John robs the bank at that exact moment. In this case, the majority of participants (more than 75%) thought that John freely robbed the bank and was morally responsible for robbing the bank. Since most people judged that John was free and morally responsible for robbing the bank in a determined world, the results suggest that most people at least sometimes have compatibilist intuitions.

However, data have since emerged indicating folk intuitions about free will and moral responsibility can be responsive to environmental or situational factors. For example, Shaun Nichols and Joshua Knobe (2007) provide evidence that folk intuitions are influenced by whether people make judgments about some abstract individual or about a person who is described in some detail. They also found that the emotional content that a scenario has could also influence folk intuitions about freedom and moral responsibility. To assess people’s intuitions about abstract questions concerning compatibilism, Nichols and Knobe (2007) provided participants with the following descriptions. Universe A is meant to describe some key elements of determinism. Universe B is meant to describe a universe where determinism is not true:

Universe A: Imagine a universe (Universe A) in which everything that happens is completely caused by whatever happened before it. This is true from the very beginning of the universe, so what happened in the beginning of the universe caused what happened next, and so on right up until the present. For example, one day John decided to have French Fries at lunch. Like everything else, this decision was completely caused by what happened before it. So, if everything in this universe was exactly the same up until John made his decision, then it had to happen that John would decide to have French Fries (Nichols & Knobe, 2007).

Universe B: Now, imagine a universe (Universe B) in which almost everything that happens is completely caused by whatever happened before it. The one exception is human decision making. For example, one day Mary decided to have French Fries at lunch. Since a person’s decision in this universe is not completely caused by what happened before it, even if everything in the universe was exactly the same up until Mary made her decision, it did not have to happen that Mary would decide to have French Fries. She could have decided to have something different.

After reading these descriptions, participants were asked which of the universes is most like ours. Not surprisingly, the vast majority (over 90%) thought Universe B (the indeterministic universe) was most like ours. When asked the following question “In Universe A, is it possible for a person to be fully morally responsible for their actions?” the vast majority (86%) said “no” (Nichols & Knobe, 2007, p. 670). However, responses changed dramatically when participants were presented with the following “concrete” paragraph in addition to the two above:

In Universe A, a man named Bill has become attracted to his secretary, and he decides that the only way to be with her is to kill his wife and 3 children. He knows that it is impossible to escape from his house in the event of a fire. Before he leaves on a business trip, he sets up a device in his basement that burns down the house and kills his family.

Seventy-two percent of participants thought that Bill was morally responsible for killing his wife in Universe A even though his action was determined. The results suggest that people can have very different intuitions depending on whether the questions are asked in abstract, general terms about actions or about concrete, specific terms about a particular person’s action.

What could explain the abstract/concrete difference? Nichols and Knobe (2007) posit that emotional reactions could explain the different intuitions about the cases. Emotions often influence people’s reactions and judgments. For example, if you are feeling angry, you are less likely to adequately acknowledge legitimate excuses for other people’s behavior. Imagine you had a bad day at work and then you come home and see that your dog has eaten the leftover pizza you left on the counter. Because you are already angry, you are less likely to think that you may have done something wrong to enable your dog to eat the pizza (e.g., leaving it out on the counter). You’ll be more likely to blame and be angry at your dog because of your antecedent bad mood than if you were not in a bad mood. In this case, emotions get in the way of how you would assess a situation if you weren’t feeling emotional. Nichols and Knobe suggest something similar may be happening in the abstract and concrete cases. Affect, or one’s experience and expression of emotions, may get in the way of one’s judgments about freedom and moral responsibility—one’s affective state results in a performance error. According to the affective performance error account, people normally have an incompatibilist theory of freedom and moral responsibility as illustrated in the abstract scenario. However, in cases with high affective content, one’s emotional reactions get in the way of one’s incompatibilist theory resulting in more compatibilist friendly intuitions as illustrated in the concrete scenarios.

To test the affective performance error model, participants received the following concretely described scenarios that varied the affect content of the action in addition to the description of Universe A above.

High Affect: As he has done many times in the past, Bill stalks and rapes a stranger. Is it possible that Bill is fully morally responsible for raping the stranger?

Low Affect: As he has done many times in the past, Mark arranges to cheat on his taxes. Is it possible that Mark is fully morally responsible for cheating on his taxes? (Nichols & Knobe, 2007)

When asked if Bill could be fully morally responsible for his actions, 64% said yes. However, only 23% said that Mark could be fully morally responsible for his actions. Hence, it appears that the affective component of the action influences people’s intuitions about moral responsibility’s relation to determinism.

The affective performance error model seems to explain the abstract/concrete difference. Abstract cases generally generate less affect than concrete cases. In some concrete cases, the action is described in enough detail such that more affect is generated.Footnote 3 Hence, depending on the affective content of the action being evaluated, people can sometimes express compatibilist and sometimes express incompatibilist intuitions. Some recent studies have cast doubt on the affective performance error model, however (Cova, Bertoux, Bourgeois-Gironde, & Dubois, 2012; Vargas, 2006). A meta-analysis of the affective performance error model suggests that while the effect of affect is real (~1% of total variance), it is not large enough to explain the large differences between the abstract and concrete cases (A. Feltz & Cova, 2014).

Nahmias, Coates, and Kvaran (2006a) also provide evidence that people’s free will intuitions are sometimes sensitive to contextual factors and offer an alternative explanation for the concrete/abstract difference. In particular, sometimes people’s free will intuitions are responsive to the nature of the description of determinism. To demonstrate this, Nahmias, Coates, et al. (2006a) created vignettes where determinism was described in “psychologically reductionistic” terms or in “psychologically non-reductionistic” terms. The reductionist scenarios (in italics below) describe mental processes in terms of brain states and processes whereas the non-reductionist scenarios (in brackets below) describe mental process in more folk-psychological terms like thoughts and desires:

Most respected neuroscientists [psychologists] are convinced that eventually we will figure out exactly how all of our decisions and actions are entirely caused. For instance, they think that whenever we are trying to decide what to do, the decision we end up making is completely caused by the specific chemical reactions and neural processes [thoughts, desires, and plans] occurring in our brains. The neuroscientists [psychologists] are also convinced that these chemical reactions and neural processes [thoughts, desires, and plans] are completely caused by our current situation and the earlier events in our lives, and that these earlier events were also completely caused by even earlier events, eventually going all the way back to events that occurred before we were born.

So, if these neuroscientists [psychologists] are right, then once specific earlier events have occurred in a person’s life, these events will definitely cause specific later events to occur. For instance, once specific chemical reactions and neural processes [thoughts, desires, and plans] occur in the person’s brain [mind], they will definitely cause the person to make the specific decision he or she makes. (Nahmias, Coates, et al., 2006a, p. 224)

The results from these scenarios were impressive. Forty percent of those in the psychologically reductionist scenario judged the person to be free and morally responsible. Eight-five percent of those in the non-reductionistic scenario judged that the person was free and morally responsible. Nahmias, Coates, et al. (2006a, p. 229) also found the same basic pattern of results using different but conceptually similar scenarios (see also Roskies and Nichols (2008)). They concluded that the way determinism is described can influence intuitions about free will and moral responsibility.

Results such as these have led some to think that sometimes people incorrectly interpret that determinism entails “bypassing” conscious agency (Nahmias, Coates, et al., 2006a; Nahmias & Murray, 2010).Footnote 4 That is, the processes that result in the action go around one’s conscious agency so one’s beliefs and desires are not interpreted as playing a role in the production of the action. If conscious agency is bypassed (e.g., one’s beliefs, desires, intentions, plans), then in some important respects it is not the person who is acting. If the person is not acting, then the person is not free or morally responsible for those actions. However, if determinism is correctly understood as “going through” conscious agency (i.e., one’s mental states are importantly involved in the deterministic causal sequence), then many people have compatibilist intuitions. In these ways, people can sometimes express compatibilist intuitions and sometimes incompatibilist intuitions depending on how they interpret determinism. Abstractly described actions are more likely to encourage an incorrect bypassing understanding of determinism. However, concretely described actions are more likely to discourage a bypassing interpretation by making it more obvious that the person is somehow importantly involved in the production of the action.Footnote 5 Hence, bypassing can explain the abstract/concrete difference in free will intuitions.

Extraversion Predicts Compatibilist Intuitions

These studies contribute importantly to the understanding of folk intuitions about freedom and moral responsibility. But of note, there is a consistent, stable, and substantial dissenting minority in all these studies. For example, A. Feltz, Cokely, and Nadelhoffer (2009) presented participants both of Nichols and Knobe’s (2007) High and Low Affect cases. Results revealed remarkable consistency in participants’ responses. When asking about whether one can be free and morally responsible, 67% of participants gave incompatibilist friendly responses to both high and low affect conditions whereas only 8% gave a mixed response. Asking about free will revealed largely the same effect. Sixty-two percent of participants gave incompatibilist matched answers and only 9% gave mixed responses. So while Nichols and Knobe’s between subjects study suggested that people can be manipulated by affect, Feltz, Cokely, and Nadelhoffer’s studies suggested that there is at least some temporal stability in judgments. This finding is consistent with the idea that there may be some relatively stable individual differences in people’s judgments about freedom and moral responsibility.

But what could account for the stability in free will judgments? One compelling possibility is that one’s personality might be partially responsible for free will and moral responsibility judgments. Many models of personality hold that that personality traits are heritable and are relatively resistant to change over time once one reaches young adulthood (but they can and do change, as well). Moreover, personality traits are associated with differences in how one thinks (e.g., those who are conscientious may take more time deliberating about a difficult problem compared to those who rate themselves lower on conscientiousness) and how one behaves (e.g., those who are high on conscientiousness may have a cleaner room than others) (Funder, 1991, 1995; McCrae & Costa, 1990). Heritable personality traits shape our interests, feelings, and reactions thereby influencing how we interact and relate to the world around us. As such, personality traits may also shape our intuitions about philosophically relevant issues such as freedom and moral responsibility.

Today, results from our research program provide substantial evidence that the global personality trait extraversion predicts how one responds to the combability question. Extraversion is one of the most fundamental dimensions of human personality, and is in some way represented in most major personality models (Lucas, Diener, Grob, Suh, & Shao, 2000). In most of the experimental philosophy research reported here and elsewhere, extraversion is measured via a validated psychological research assessment designed to measure individual differences in the Five Factor model of personality (extraversion, agreeableness, openness to experience, emotional stability, and conscientiousness) (John & Srivastava, 1999). Within the Five Factor model, an extravert is defined as one who is a “communicative, sociable, energetic person who thrives on social contact and who does not regulate tightly his/her emotional reactions” (Akert & Panter, 1988, p. 966). Extraverts enjoy social interaction, find social interaction rewarding, and actively seek out and are motivated to engage in social interactions (Ashton, Lee, & Paunonen, 2002; Lucas et al., 2000).

While there are many features that characterize and help identify what an extravert is, one feature that is particularly relevant for our purposes is the social nature of extraverts. In general, one tendency of extraverts is that they are more sensitive to and understand interpersonal dynamics better than introverts (Akert & Panter, 1988). To illustrate more concretely, extraverts are often better at understanding non-verbal communication compared to introverts. Extraverts also tend to enjoy social interaction, and perhaps partially as a function of that, they have different and socially minded judgment process, interpretations, and memories (Chamorro-Premuzic, Furnham, & Ackerman, 2006; Lucas & Fujita, 2000; Rusting & Larsen, 1997; Zelenski & Larsen, 2002). As we mentioned at the beginning of the chapter, beliefs about freedom and moral responsibility are fundamental elements of how we relate to ourselves and others. In other words, beliefs about freedom and moral responsibility can serve important social functions. So, it stands to reason that extraverts could potentially be differentially influenced by features of cases involving freedom and moral responsibility, and may have systematically different intuitions about those cases compared to introverts.

These general tendencies among extraverts suggest that they may interpret or interact with the materials in the Free Will Scenarios differently from those who are not extraverted. These interpretations or interactions may be especially pronounced when the action that people are asked to make judgments about is something that violates social norms such as killing somebody. In those cases, because of extraverts’ judgment tendencies, extraverts may have different reactions to those cases just like they may have different reactions to situations in real life compared to non-extraverts. Just to illustrate, extraverts tend to value having social interactions that are not contentious and are pleasant. If that is right, then when an extravert makes a judgment about somebody who engages a contentious and unpleasant action, extraverts’ judgment tendencies may be triggered and override any of the potential excusing conditions for that action (e.g., that the person’s action was completely caused by what happened before). Those excusing conditions may have relatively less weight (or go unnoticed) because of the socially aberrant or affective nature of the action they are asked to make judgments about. Rather, extraverts’ judgments may be primarily driven by a desire to maintain social balance and harmony. In other words, extraverts may judge a person to be free and morally responsible because holding them to be free and morally responsibly is socially important (for related line of reasoning, see Smilansky (2002)).

Given that there are some good theoretical reasons to suspect that extraversion is related to compatibilist intuitions, it still remains to be seen whether extraversion is in fact related to compatibilist intuitions. Efficiently establishing this relation requires actually conducting some studies to measure the relation between extraversion and compatibilism. Typically, this involves presenting some description of determinism, measuring responses to that description, and then estimating the relation of responses to the global personality trait extraversion. There are a number of ways to describe determinism, a number of different ways to measure responses to those descriptions, and a number of different groups of people whose intuitions could be measured. Having different possible descriptions, response options, and possible samples provide challenges and opportunities. The challenge is that some way to describe determinism and measure responses has to be chosen. But there is no widely agreed upon single best way to describe determinism. All ways of describing determinism can be criticized as not capturing, or not communicating, the central aspects of determinism (A. Feltz et al., 2009; J. Turner & Nahmias, 2006). Additionally, one has to choose the prompts and the response options (e.g., yes/no, rating agreement, open-ended responses, etc…), each having their own strengths and weaknesses. Finally, one has to select the relevant group of people. If one wants to know what professional philosophers think about freedom and moral responsibility, it would be a poor strategy to select people who have no training in philosophy. A decision must be made about how best to ensure representative sampling and assessment.

Having multiple descriptions of determinism and ways to respond is also an opportunity. By presenting different groups of people with different descriptions of determinism and offering different methods of responses, we can begin to estimate the extent to which evidence and intuitions converge while mapping out the range and stability of the intuitions that people express about determinism. This is particularly important for predicting intuitions with personality traits because one worry is that a personality trait could be related to just one description of determinism, group of people, or set of response options. If that were the case, then extraversion may not be related to compatibilist intuitions but rather something more specific about one scenario, sample, or handful of response options. If those descriptions and response options converge on the same general pattern across theoretically related assessment instruments and samples, then there is good reason to suspect that people’s responses are not only dependent on idiosyncratic features. That pattern of results would converge to provide compelling evidence that some people have deep-seated compatibilist intuitions that are robustly related to their personality.

While theoretical reasons can guide decisions about materials, response options, and target populations to some degree, at one point a choice has to be made. In one of the seminal studies to demonstrate empirically the relation between extraversion and compatibilist intuitions, a psychologically non-reductionistic scenario based on the scenarios used by Nahmias, Coates, et al. (2006a) was chosen to describe determinism (A. Feltz & Cokely, 2009). One reason this scenario was chosen was because it is very similar to the general types of scenarios used to measure compatibilist judgments. In this sense, the scenario was chosen because it was “industry standard”Footnote 6 and many if not most experts agreed it represented key features of determinism. The scenario was identical to the psychologically non-reductionistic scenario above except that the second paragraph was replaced with the following paragraph:

High Affect

So, once specific earlier events have occurred in a person’s life, these events will definitely cause specific later events to occur. For example, one day a person named John decides to kill his wife so that he can marry his lover, and he does it. Once the specific thoughts, desires, and plans occur in John’s brain, they will definitely cause his decision to kill his wife.

Fifty-eight participants were asked to rate how much they agreed with the following statements on a 7-point Likert scale (1 = strongly disagree, 4 = neutral, and 7 = strongly agree)Footnote 7:

  1. 1.

    “John’s decision to kill his wife was ‘up to him.’

  2. 2.

    John decided to kill his wife of his own free will.

  3. 3.

    John is morally responsible for killing his wife.”

We will refer to this group of items (1–3) as the free will questions since they are some of the standard questions used to assess compatibilist intuitions. As we will see, responses to these three prompts are almost always strongly correlated with one another. Participants were also given the Ten Item Personality Inventory (TIPI) (Gosling et al., 2003), which involves the same set of questions introduced in Chap. 1. We will focus on the two items that make up the extraversion scale in the TIPI. (You can check your scores again from Chap. 1 to see if our results match with your experience with the scenarios.)

Figure 2.1 presents proportions of participants’ responses dichotomized according to whether participants agreed (response > 4), were neutral (response = 4), or did not agree (response < 4) to the free will questions:

Fig. 2.1
3 pie charts of up to him, free will, and responsible. In all 3 pie charts the response in descending order are as follows. 1, Compatibilists. 2, Incompatibilists. 3, Neutral.

Percent of response to the free will questions

Replicating Nahmias, Coates, et al. (2006a) study, most people agreed that the person was free and morally responsible. The mean response for all questions was on the agreement side of the scale, suggesting that the mean response was compatibilist friendly.Footnote 8

We estimated the correlations between the three free will questions (questions 1–3 above). These estimates suggested that there were strong relations among the responses to the three questions (rs > .7). When items are so strongly correlated with one another it suggests that, to a great extent, they are all likely measuring the same basic thing. So a composite compatibilism score was calculated ((answers to the three free will prompts)/3). We then calculated correlations among each of the three free will questions, the composite score, and extraversion. Extraversion was related to each of the 3 free will questions as well as the composite score. In short, as one’s extraversion level went up so too did agreement with the free will questions. However, when we calculated the correlations with the other Big Five personality traits, gender, and other general cognitive abilities (e.g., cognitive impulsivity), no other statistically significant correlations were found (see Table 2.1).

Table 2.1 Correlations of participants’ responses (N = 58)

To further illustrate these relationships, we divided participants into four groups (i.e., quartiles) depending on how they scored on the extraversion subscale of the TIPI. Then we performed what is sometimes called an “extreme groups analysis” (Cokely, Kelley, & Gilchrist, 2006). That means that we took those who were in the top extraversion quartile and compared those participants to those who were in the bottom extraversion quartile. The reasoning is that in an extreme groups analysis, we should see the differences between those who are highest in the trait of extraversion and those who are the lowest. That is what the extreme groups analysis found (see Fig. 2.2). Those in the bottom extraversion quartile had statistically significant lower, and arguably qualitatively different (i.e., neutral) free will judgments compared to those in the top quartile (Cohen’s d ranging from .6 to .9).

Fig. 2.2
A double bar graph plots high extraversion and low extraversion. Up to him. High extraversion, 6. Low extraversion, 4.3. Free will. High extraversion, 5.9. Low extraversion, 4.4. Responsibility. High extraversion, 6. 3. Low extraversion, 5. Data are estimated.

Low (bottom quartile) and high (top quartile) extraversion scores by level of agreement with Up to him, Free will, and Responsibility statements. Error bars represent the standard error of the mean

These results suggest that extraversion was a reliable predictor of some compatibilist intuitions. To summarize, the correlation table presented in Table 2.1 suggested that extraversion was moderately related to free will judgments in the predicted direction. As one is more extraverted, one tends to agree more strongly that the person has free will and is morally responsible. This general pattern was further illustrated by an extreme groups analysis based on extraversion quartiles. And, as we have noted, on at least two of the free will questions, there was arguably a qualitative shift where people who were low in extraversion did not agree that the person was free nor did they agree the action was up to him.

An increasingly important element in psychology, and science more generally, is replication. By some estimates, more than 50% of findings reported in leading journals in medicine, science, genetics, etc., is likely to fail to replicate. If the previous study were the only piece of evidence that extraversion predicts compatibilist intuitions, then we would have limited reason to think that extraversion generally and robustly predicts compatibilist intuitions. After all, the results from this one study could have capitalized on chance (Type I error or a statistical false alarm) or may have been related to specific features of the scenarios, participants, or responses options rather than reflecting something deep and enduring about compatibilist intuitions. While the statistical analyses suggest these results were likely to generalize, some caution is merited when interpreting the results of just one study of 50 young adults living in the United States.

Fortunately, the relation between extraversion and compatibilist intuitions has since been replicated many different times in different labs, in different countries, with different and diverse samples, using different descriptions of determinism and response options (Andow & Cova, 2016; E. T. Cokely & Feltz, 2009a; A. Feltz, 2013, 2015a, 2015b; A. Feltz & Cokely, 2008; A. Feltz & Millan, 2015; A. Feltz, Perez, & Harris, 2012b; Nadelhoffer, Kvaran, & Nahmias, 2009; Schulz, Cokely, & Feltz, 2011). There are of course some exceptions and some people who think the exact opposite of what we’d expect, but the strength of the observed relationship as estimated in the seminal study has been generally consistent across studies. Using a technique called meta-analysis, we were also able to rigorously combine the results different, discrete studies. This statistical combination aimed to provide the “best available” estimate of relation between extraversion and compatibilist intuitions. This technique generally helps alleviate many of the worries of findings based on individual studies, such as the risk of capitalizing on chance relations. The best meta-analytic estimate at the time of writing this chapter is that the overall average relation between extraversion and compatibilist intuitions is about .2 (95% CI .15–24) (A. Feltz & Cokely, 2019). We have included a figure (sometimes called a Forest Plot) to illustrate the size of the effects for each individual study reviewed (see Fig. 2.3).

Fig. 2.3
A forest plot plots Fisher's z Transformed Correlation Coefficient. Feltz, 2013 has the highest value at 0.52, followed by Feltz and Cokely, 2009 at 0.35, and Feltz and Millian, 2015 at at 0.35.

Forest plot of effects in studies about the relation between free will judgments and extraversion

The square dot in the middle of the lines for each study represents the sample size of that study—bigger squares mean bigger samples and therefore they are weighted more heavily in the overall estimate of the overall effect size. The lines surrounding the box are confidence intervals. The confidence interval represents an analytic estimate depicting the precision of the estimated interval (e.g., the true size of the effect is very likely to fall somewhere within that range). Theoretically, if all the studies are estimating the same underlying relation (i.e., extraversion’s correlation with compatibilist intuitions), then 95% of all studies should have a confidence interval that includes that true value (and 5% should not). This theoretical pattern is what we see with the relations between extraversion and compatibilist intuitions. Nearly all the studies have a confidence interval that includes .2, the best estimate of the relation. The diamond at the bottom of the figure represents the overall mean correlation based on the studies analyzed and the edges of the diamond represent the confidence interval for the overall mean correlation.

The result of the meta-analysis suggests that there is a robust, stable relation between extraversion and compatibilist intuitions across labs, testing environments, and sampling techniques. To put the estimated strength of the average relationship between extraversion and compatibilism in perspective, it is about the same as the estimated general strength of the relationship between human weight and sex. Yes, some women weigh more than some men, but most of the time it’s a good bet that a random group of men will outweigh a random group of women by a substantial margin, just as a random group of extraverts will on average feel much more strongly about compatibilism than a random group of introverts, regardless of their education, income levels, general cognitive abilities, decision making skills, cultural backgrounds, ages, or gender identities. The effect is strong enough that it implies that most of the time a United States Congress consisting of all extraverts would vote differently than a Congress consisting of all introverts when voting on censures condemning the behaviors of politicians.

Determinism, Fatalism, and Individual Differences

Some theorists have worried that participants do not fully understand the deterministic nature of the scenarios used to measure compatibilist intuitions (A. Feltz et al., 2009; A. Feltz, Tanner, Hoang, Holt, & Muhammad, 2022; J. Turner & Nahmias, 2006). The worry is reasonable because the philosophical sense of determinism is highly technical and nuanced. The notion (i.e., a full definition of the word “determinism”) is not likely to be reflected in vernacular and is not likely to be well understood by many non-experts. The difficulty with determinism was partially the impetus to provide people with descriptions of determinism in scenarios rather than just a definition. Given the scenarios approach, it could be relatively easy for some participants to incorrectly interpret or incompletely process the deterministic information presented in the scenarios. For example, J. Turner and Nahmias (2006) and A. Feltz et al. (2009) have commented that the scenarios used by Nichols and Knobe (2007) and Nichols (2004b) may encourage some people to understand the scenarios fatalistically. Fatalism as we will use the term is “the thesis that whatever happens must happen; every event or state of affairs that occurs, must occur, while the nonoccurrence of every event and state of affairs is likewise necessitated” (Bernstein, 2002, p. 65). Nichols and Knobe (2007) and Nichols (2004b) use scenarios that describe an agent as “having to” act a certain way. But actions do not “have to happen” in a deterministic world. If laws of nature or initial conditions had been different, then different actions could have come about. Actions that are fated must happen regardless of the causal nature of the universe, the laws of nature, or any state of the universe (Bernstein, 2002). As such, the language used by Nichols and Knobe may encourage a fatalistic rather than a deterministic understanding of the scenarios. Moreover, many compatibilists believe that fated actions are not done freely. If participants do not appropriately understand the deterministic nature of the scenario, then their responses do little to help illuminate the compatibility question, much less extraversion predicting compatibilist intuitions. Hence, it is difficult but critically important to convey to non-philosophers an accurate notion of determinism that does not encourage an unwanted understanding of the scenarios (e.g., fatalism, indeterminism) if folk intuitions are to help inform answers to the compatibility question (see also Nadelhoffer, Rose, Buckwalter, & Nichols, 2020a).

A. Feltz and Millan (2015) tested whether people can appreciate the difference between fatalism and determinism. In a variety of different scenarios, they found that overall people had different intuitions about some determined v. fated actions.Footnote 9 Here’s one fatalistic scenario they used:

Book: There is a special book that has all of our decisions and actions truly written in its content. For instance, whenever we are trying to decide what to do, the decision we end up making is completely and truly written in this book. The special book has these events truly written in it lifetimes before the events took place.

So, if the book has an event written in it, the event will definitely occur. For example, one day a person named John decides to kill his wife so that he can marry his lover, and he does it. Once the specific event is truly written in the book, it is impossible for John not to kill his wife.

Assume the book’s contents made it impossible for John not to kill his wife. Please rate to what degree you agree with the following statements.

Participants responded on a 7-point scale (1 = strongly disagree, 7 = strongly agree). A separate group of participants also received a low affective version of the fatalism case describing John cheating on his taxes. Participants answered the free will questions along with the following comprehension question “If the universe were re-created with the special book having the same true sentences, John would do the same thing?”. Two separate groups of participants received only one of the high and low affect scenarios based on Nahmias, Coates, and Kvaran’s determinism scenarios. Overall, participants had different patterns of responses to fated and determined actions (see Table 2.2 for means and standard deviations). Those in the Book scenario had statistically significant, and large, differences in free will judgments compared to those in the Determinism scenario (of note, these studies did not detect a reliable difference of affect and affect did not interact with conditions). In these studies, extraversion was related to responses to the determinism scenario but not to the fatalism scenario. To provide evidence for that relation, they conducted a hierarchical linear regression that first entered (1) high/low affect and (2) Sex to control for variance that could be associated with those variables. Then they entered the extraversion score into the model. The overall model significantly predicted compatibilist judgments F (3, 51) = 8.64, p < .001, R2 = .34. Even after controlling for high/low affect and sex, extraversion continued to predict unique variance, β = .35, t = 1.97, p = .05, R2change = .05. However, when they performed the same analyses using responses to the Fatalism scenario, they did not find a reliable relation between extraversion and responses to the Fatalism scenario (t < 1).

Table 2.2 Means and standard deviations for Fatalism and Determinism scenarios

These results were replicated in a subsequent study with the same materials using a within-subject design (i.e., the same people made judgments about both vignettes but at different times). Participants were given one pair of either fatalism and determinism high effect or fatalism and determinism low effect, counterbalanced for order. Participants answered the same free will questions used in previous studies. A mixed-model ANOVA with the two composites scores as within-subjects factors and order of presentation and affect as between subject factors revealed the main effect of Fatalism (M = 3.85, SD = 2.24) and Determinism (M = 5.58, SD = 1.55): F (1, 63) = 41.03, p < .001, ηp2 = .39. Neither order of presentation (F (1, 63) = 1.89, p = .28, ηp2 = .02) nor affect (F (1, 63) = 1.16, p = .29, ηp2 = .02) interacted with judgments. A hierarchical linear regression was constructed to test extraversion’s relation to the compatibilist composite score after controlling for affect, order, and sex. The full model was a near significant predictor of compatibilist judgments F (3, 67) = 2.23, p = .065, R2 = .11. After controlling for affect, order, and sex, extraversion predicted unique variance in the compatibilist composite score, β = .12, t = 2.0, p = .05, R2change= .06. Once again, extraversion did not predict judgments in the fatalism scenario (t < 1). These results have also been replicated by a different research group (Andow & Cova, 2016).

Feltz and Millan also reported evidence from a third experiment including the scenarios from Nichols and Knobe (2007). Since there was no reliable effect of affect, the third experiment used only high affect cases. Participants received Book along with Nichols and Knobe’s High Affect scenario. Participants responded to the free will questions. A mixed-model ANOVA with the two composites scores as within-subjects factors and order of presentation as between subject factors revealed an overall main effect between Book (M = 3.75, SD = 2.21) and the determinism scenario (M = 5.21, SD = 1.92) F (1, 92) = 40.37, p < .001, ηp2 = .31. A hierarchical linear regression with (1) order, and (2) sex and (3) extraversion was a significant predictor of compatibilist judgments F (3, 89) = 2.81, p = .03, R2 = .10. After controlling for order of presentation and sex, extraversion continued to predict unique variance in the compatibilist composite score, β = .16, t = 2.14, p = .04, R2change = .05. Extraversion did not reliably predict unique variance for the fatalism composite score (t = 1.03, p = .31).

This series of studies suggests everyday intuitions about fated and determined actions tend to be different. Overall, people are more likely to think that one is freer in a determined scenario than in a fated scenario. These studies also suggest that there is something unique about determined actions that is responsible for the relation to extraversion since the relation between extraversion and fated actions was not found. Therefore, we have some evidence that extraversion is specifically related to compatibilist intuitions and not to similar but conceptually distinct threats to freedom and moral responsibility such as fatalism. In the next section, we will see that this pattern of unique predictive ability of extraversion persists for another threat to freedom and moral responsibility—i.e., manipulation.

Free Will and Manipulation

The experimental exploration of free will has largely centered on directly assessing the compatibility question. Direct assessments of the compatibility question probe specific intuitions about the relations of determinism, freedom, and moral responsibility. Tamler Sommers (2010, 2014) argues that this general approach is a mistake—or is at least incomplete. While assessing and documenting intuitions about the compatibility question can be interesting, that’s not what philosophers do. Rather, in typical philosophical practice, philosophers give reasons for thinking that some claims are true. These reasons typically are incorporated into an argument for some conclusion. Typically, experimental philosophy does not assess the arguments or reasons that philosophers give for thinking some philosophical claims are true. Most experimental philosophy instead assesses intuitions about the conclusions of those arguments.

To illustrate, one way that experimental philosophers have taken the results of studies to be important is that they help situate argumentative burdens. That is, those results can indicate which views are counter-intuitive. Give the counter-intuitiveness of the positions, those philosophers have to offer additional reasons why their views are correct (or why those with views consistent with the dominant view are wrong) while those with positions supported by folk intuitions do not. In the free will debate, that might suggest that those with incompatibilist intuitions have some additional argumentative burden that compatibilists do not have because compatibilism seems supported by folk intuitions. However, Sommers argues:

[I]ncompatibilists can accept that they have this ‘argumentative burden’ but claim that they have discharged it with, well, arguments. After all, van Inwagen’s ‘consequence argument’, Strawson’s ‘basic argument’, and Pereboom’s ‘four case argument’, to name just a few, are designed to precisely lead the reader to the conclusion that determinism precludes free will and moral responsibility... It would seem that in order to truly test the plausibility of the incompatibilist position, we need to examine the intuitions supporting the premises and principles of their argument... (2010, pp. 205–206)

Sommers goes on to argue that starting with a conclusion being correct just begs the question—something that philosophers seldom do and very few think this is a good argument form. Rather, philosophers may have some view and then they offer arguments for those views. Those arguments don’t beg the question, so claiming that some view is counter-intuitive simply does not appreciate something important—namely, the reasons given for that incompatibilist conclusion.

Rather than directly assessing the intuitiveness of conclusions of arguments, Sommers suggests testing the reasons that philosophers give for thinking those conclusions are true. For example, Sommers suggests testing the intuitiveness of the four case argument for incompatibilism (Pereboom, 2001). The four case argument is at least in part designed to call into question a key claim made by many compatibilists. Compatibilists often claim that if one’s psychological states are related in the right way with the production of an action, then in those conditions one can be free and morally responsible in deterministic environments. Some of these psychological states involve not being constrained to act (Hume, Selby-Bigge, & Nidditch, 1978), having desires play the right causal role in the production of an action (Ayer, 1952), having the action issue from the character of the individual (Hume et al., 1978), having first-order desires matching with second-order desires (Frankfurt, 1971), being moderately reasons responsive (Fischer & Ravizza, 1998), and being able to appreciate and act from moral reasons (Wallace, 1994). Following Pereboom, we call these kinds of psychological states “causal integrationist” conditions.Footnote 10

As will become a common theme in this book about philosophical concepts in general, there is lots of philosophical debate about the causal integrationist conditions (e.g., which conditions are the right ones, are they really sufficient, etc…). One argument that has been offered to suggest that the causal integrationist conditions are not sufficient is Pereboom’s “four case argument.” The general goal of the four case argument is to start with a scenario where one is obviously not free and morally responsible. Then, through modest changes to the scenario that do not change the judgment about the protagonist’s freedom and moral responsibility, end up with a case that describes determinism. The actual sequence of scenarios involves many of the prominent causal integrationist conditions and the following: (1) A completely manipulated person, (2) A programmed person, (3) An indoctrinated person, and then finally (4) A determined person. If Pereboom is right, then most people would judge the person in 1 as not free or morally responsible. Pereboom then claims that “an agent’s non-responsibility under covert manipulation generalizes to the ordinary [deterministic] situation” (2001, p. 112). Pereboom predicts: “If I am right, it will turn out that no relevant difference can be found among these cases that would justify denying responsibility under covert manipulation while affirming it in ordinary deterministic circumstances, and that this would force an incompatibilist conclusion.” Sripada (2012) has formalized the argument as the following:

  1. 1.

    A manipulated person is not free.

  2. 2.

    There is no relevant difference between a manipulated person and a person in a deterministic world.

  3. 3.

    If there is no difference between a manipulated person and an agent in a deterministic world, then a person in a deterministic world is not free.

  4. 4.

    Therefore, a person in a deterministic world is not free. (C. S. Sripada, 2012)

As Sripada’s formalization highlights, the intuitions about the four case argument are support for premises in an argument. In particular, the four case argument is supposed to support premise 1 and 2. After that, and along with some basic logic, we are supposed to support the incompatibilist conclusion in 4. Of course, it is an open question about how widely shared Pereboom’s intuitions about the four case argument are. But perhaps more importantly, are these intuitions systematically related to personality?

To test the extent to which people shared intuitions consistent with Pereboom’s prediction about the four case argument and whether personality predicts those intuitions, we modified cases that were used in the four case argument. Special attention was paid to making the cases accessible and understandable to most people (fancy jargon, like that expressed in the causal integrationist conditions above, was not used), and the same general approach Sripada (2012) used was adopted. Following the stipulations of Pereboom’s four case Argument, each case involves a person who arguably meets at least some of the causal integrationist conditions. Participants were assigned to one of two conditions. The first condition, people received all four cases in order. In the other condition, participants only received the final case that is meant to approximate a scenario where determinism is true. Everyone read the following paragraph (A. Feltz, 2013):

One day Bill sees a woman named Mrs. White as she is jogging in the park. Bill hates this woman, and deliberates about what to do. After weighing his options, Bill decides he should kill her. Bill’s mind is not clouded by rage or other extreme emotions. Rather, Bill thinks clearly and carefully about his own desires and values, and only then makes a decision. After he kills Mrs. White, Bill reflects on his action. He wholeheartedly endorses what he has done. BUT, there is more you need to know about Bill, and how he came to be the person he is now…

Then, participants read the following depending on which condition they were assigned (all four in one condition versus only the last paragraph in the other condition):

Intentional Direct Manipulation

Bill is essentially a normal man, but he was created by neuroscientists who directly manipulate all of his decisions. The neuroscientists manipulate Bill to make decisions that almost always benefit him. The neuroscientists implant in Bill a desire to kill Mrs. White. He is able to regulate his behavior by moral reasoning and act differently in different situations with different reasons, but in the present circumstances, the desire to kill Mrs. White is stronger than any competing desire. As a result of the neuroscientists’ implanting in Bill the desire to kill Mrs. White, Bill decides to kill Mrs. White and does it. Reflecting on the action afterward, Bill identifies with the desire to kill Mrs. White and the resulting action.

Intentional Indirect Manipulation

Bill is essentially a normal man, but he was created by neuroscientists who do not control him directly, but have programmed his genes so that he makes decisions that almost always benefit him. The neuroscientists program Bill to have a desire to kill Mrs. White. He is able to regulate his behavior by moral reasoning and act differently in different situations with different reasons, but in the present circumstances, the desire to kill Mrs. White is stronger than any competing desire. As a result of the neuroscientists’ programming Bill to have the desire to kill Mrs. White, Bill decides to kill Mrs. White and does it. Reflecting on the action afterward, Bill identifies with the desire to kill Mrs. White and the resulting action.

Culture

Bill is essentially a normal man, but he was extensively trained by his community to make decisions that almost always benefit him. He could not have prevented this extensive training, and it is ingrained in him. The extensive training generates in Bill a desire to kill Mrs. White. He is able to regulate his behavior by moral reasoning and act differently in different situations with different reasons, but in the present circumstances, the desire to kill Mrs. White is stronger than any competing desire. As a result of the extensive training generating in Bill the desire to kill Mrs. White, Bill decides to kill Mrs. White and does it. Reflecting on the action afterward, Bill identifies with the desire to kill Mrs. White and the resulting action.

Determinism

Bill is a normal man raised under normal circumstances. Every decision that Bill makes is completely caused by his genes and his cultural environment. He is able to regulate his behavior by moral reasoning and act differently in different situations with different reasons, but in the present circumstances, the desire to kill Mrs. White is stronger than any competing desire. As a result of his genes and his cultural environment generating in Bill the desire to kill Mrs. White, Bill decides to kill Mrs. White and does it. Reflecting on the action afterward, Bill identifies with the desire to kill Mrs. White and the resulting action.

Then participants responded to each of the following prompts (1 = strongly disagree, 7 = strongly agree).

  1. 1.

    “Bill kills Mrs. White of his own free will.

  2. 2.

    Bill’s killing of Mrs. White is ‘up to him.’

  3. 3.

    Bill is morally responsible for killing Mrs. White.

  4. 4.

    Bill is blameworthy for killing Mrs. White.

  5. 5.

    Bill deserves to be punished for killing Mrs. White.

  6. 6.

    Bill should be prevented from killing Mrs. White.”

Consistent with the inter-relations of free will questions noted above, the responses to 1–6 were related to one another. So, for ease of analysis, a composite score that was the mean of 1–6 was calculated. The responses in the four case condition were inconsistent with Pereboom’s prediction. There was a statistically significant difference among the conditions where people judged the person to be not free or morally responsible in the Intentional Direct Manipulation case (M = 3.88, SD = 1.6). But participants were in increasing agreement that the person in the subsequent scenarios was free and morally responsible: Intentional Indirect Manipulation (M = 4.28, SD = 1.54), Culture (M = 4.91, SD = 1.61), and Determinism (M = 5.71, SD = 1.61).

But what about personality’s relation to the judgments in the four case condition and the single case condition? As in the studies reviewed above, participants completed the TIPI (Gosling et al., 2003). The relation of personality with the mean of judgments to prompts 1–6 was assessed. In the single Case condition, once again the relation of extraversion with compatibilist judgments was replicated r (46) = .48, p = .001. However, extraversion was not related to compatibilist judgments to Determinism in the four case condition: r (40) = −.17, p = .31. Rather, in the four case condition a different personality trait was related to judgments. Emotional stability was positively related to judgments: Intentional Direct Manipulation r (40) = .27, p = .09, Intentional Indirect Manipulation r (40) = .31, p = .05, Culture r (40) = .32, p = .04, Determinism r (40) = .34, p = .03. No other personality trait was related to judgments in the four case condition (all other p’s > .13). This study thereby replicated the effect of extraversion for compatibilist intuitions (i.e., in the single Case condition) yet found another relation of a global personality trait with a series of studies involving manipulation. It appeared that those who were emotionally less stable were more likely to be influenced by the manipulation scenarios that occurred earlier in the series, which reduced their strength of agreement with a person’s freedom and moral responsibility in later cases.

The effect of emotional stability was surprising and unanticipated. Sound and responsible scientific practice necessitates a replication in cases like these. A common strategy in such cases is to develop a study to “replicate and extend” (e.g., doing the important work of confirming the unexpected finding but doing so in the context of what is generally more prized by scientists—advancing a frontier). So that’s what was done with one important modification to the four cases. Mele (2006) speculates that people may be responsive to the nature of the manipulator in the four cases presented above. In particular, in each of the two manipulator scenarios, there was intentionality behind the actions of the protagonist (e.g., in the Direct Manipulation scenario, the neuroscientists intentionally manipulate all of Bill’s actions). In the other scenarios, there was no intentionality to the influence on Bill’s actions.

To help address this issue in the replication study, the manipulation in the first two cases was changed to be the result of a brain tumor that either completely manipulates all Bill’s actions or programs him to behave as he does (e.g., “Bill is essentially a normal man, but he has a brain tumor that directly manipulates...”). It is plausible to think that the brain tumor does not manipulate Bill intentionally, so this change should satisfy Mele’s concern about the original four cases. Again, participants in this study were either given all four cases or were in the single case condition.

Results of the new replication and extension study were again contrary to Pereboom’s prediction and the means for each case was roughly similar to those observed in the first four case study. The same correlations of personality with free will judgments was also observed: extraversion was positively related to the single case Determinism composite score, r (90) = .20, p = .056; however, this relation was again not found in the four case scenario: r (89) = .03, p = .80. Nevertheless, emotional stability was again related to intuitions in three of the four cases in the revised four case scenario: Non-Intentional Direct Manipulation r (89) = .33, p = .001, Non-Intentional Indirect Manipulation r (89) = .32, p = .003, Culture r (89) = .08, p = .48, Determinism r (89) = .22, p = .04.

The series of manipulation studies provided additional converging evidence for the relation of extraversion and compatibilist intuitions. In both of the single case Determinism scenarios, extraversion predicted compatibilist responses. This relation was eliminated in the four case condition, again indicating that extraversion predicts specific kinds of free will and moral responsibility judgments. Indeed, in the four case scenarios, extraversion did not predict compatibilist intuitions in the determinism scenario. Rather, a different general personality trait, emotional stability, predicted intuitions in the four case scenarios.

The differential predictive ability of different personality traits should be expected since it simply is not the case that any single personality trait (e.g., extraversion) should predict all attitudes about freedom and moral responsibility. That would be similar to saying that a single personality trait should predict all attitudes about other broad domains (e.g., friendship, justice). Judgments about freedom and moral responsibility are diverse and complicated, and therefore are likely to be most efficiently predicted with a variety of personality traits. However, for our purposes, what is important is to identify the extent to which any one personality trait can reliably and robustly predict judgments about freedom and moral responsibility.

Free Will, Individual Differences, and Language

All the studies reviewed thus far have been conducted in English with samples drawn from the United States. This leaves open the following question: Does personality predict intuitions in different languages and cross-culturally? There are some reasons to think that personality would predict across cultures and demographics, as well as some reasons to think that personality would not. One reason personality may not predict intuitions about free will and moral responsibility is that there are some cross-cultural differences in cognition. To take one example, East Asian people tend to be more holistic than Westerners (Nisbett, Peng, Choi, & Norenzayan, 2011). Westerners have a greater tendency to attribute the causes of actions to internal mental states of the person whereas Easterners tend to focus more on the context in which the actions originated (Morris, Nisbett, & Pent, 1995). In this sense, East Asians may take the deterministic (or other contextual) factors of a person’s action more seriously compared to Westerners who tend to focus on internal mental states (e.g., thoughts, desires, and beliefs). So, the different focus may eliminate the relation of personality to freedom and moral responsibility intuitions. A second reason is that there are some instances of cultural variability in philosophically relevant intuitions. Some semantic intuitions (Machery, Mallon, Nichols, & Stich, 2004) and some epistemic intuitions (J. Weinberg, Nichols, & Stich, 2001) vary as a function of culture, although some of these effects have been somewhat difficult to replicate (Lam, 2010; Seyedsayamodst, 2015; Ziółkowsk, Wiegmann, & Horvath, 2023), while others have successfully replicated (e.g., Gödel cases) (Dongen, Colombo, Romero, & Sprenger, 2020), see Cova et al. (2021)).Footnote 11 So, given the variation, there is some reason to think that the relation to personality might not be reliably present in other cultures.

However, there are some good reasons to think that personality would predict free will and moral responsibility intuitions cross-culturally. Sarkissian et al. (2010) examined possible cross-cultural differences in intuitions about free will and moral responsibility in India, Hong Kong, Columbia, and the United States. They gave participants a typical scenario describing determinism like those presented above. They then asked the abstractly framed question “is it possible for a person to be fully morally responsible for their actions?”. There were no significant cross-cultural differences in responses. Consistent with the concrete/abstract different in free will intuitions, the majority of participants across the different regions of the world thought that moral responsibility was not compatible with determinism in this abstract frame (63–75%).

If Sarkissian and colleagues are correct that some intuitions about free will are a cultural universal, then judgments about concretely described individuals would likely be compatibilist friendly cross-culturally (reflecting the abstract/concrete difference).Footnote 12 Moreover, the relation of extraversion to judgments of freedom and moral responsibility is likely to persist across cultures because there is little difference in personality between people in the United States and South America, Western Europe, and Southern Europe (Schmitt et al., 2007).

We will review three studies suggesting that extraversion is likely to predict compatibilist judgments cross-culturally. In one of our studies (Schulz et al., 2011), we found that extraversion predicts compatibilist intuitions in a sample of adults of various ages and education residing in Germany. Participants were given the following determinism scenario (in German):

Most respected neuroscientists are convinced that eventually we will figure out exactly how all of our decisions and actions are entirely caused. For instance, they think that whenever we are trying to decide what to do, the decision we end up making is completely caused by the specific chemical reactions and neural processes occurring in our brains. The neuroscientists are also convinced that these chemical reactions and neural processes are completely caused by our current situation and the earlier events in our lives, and that these earlier events were also completely caused by even earlier events, eventually going all the way back to events that occurred before we were born.

So, if these neuroscientists are right, then once specific earlier events have occurred in a person’s life, these events will definitely cause specific later events to occur. For instance, once specific chemical reactions and neural processes occur in the person’s brain, they will definitely cause the person to make the specific decision he or she makes. So, once specific earlier events have occurred in a person’s life, these events will definitely cause specific later events to occur.

For example, one day a person named John decides to kill a shop owner, because he needs money and does it. Once the specific thoughts, desires, and plans occur in John’s mind, they will definitely cause his decision to kill a shop owner.

After reading this scenario, participants were given the free will questions.

Responses to the free will questions were highly correlated (.48, .52, .67; p < 0.05 for all) so a composite free will score was calculated for the free will questions. In this case, participants responded to a more detailed measure of extraversion from the NEO-PI-R (Costa & McCrae, 1992, German version: John et al., 2004). On this measure, as is consistent with personality theory in general, the global trait extraversion is constituted by smaller factors called facets. One of these facets of extraversion is warmth. In this study, only warmth was related to compatibilist judgments explaining about 6% (p = 0.005) of the variance in compatibilist judgments.

Two more recent studies we conducted also suggest that the relation of extraversion to compatibilist judgments persists in Spanish. In the first recent study, 129 participants were recruited from Amazon’s Mechanical Turk. All materials used to recruit participants were in Spanish. We included some data quality control measures. Nine participants were excluded for not completing the survey and four were excluded for requesting that their answers not be used. Since the materials were in Spanish, we wanted to have some indication that the participants spoke Spanish, so we included a comprehension test in Spanish (see Appendix to this chapter). Forty-five were excluded for incorrectly answering at least one of the Spanish comprehension questions. Seventy-one participants remained for analyses. Fifty (70%) identified as male.

Participants were randomly assigned to receive the Spanish version of only one of either the Determinism High Affect or Determinism Low Affect scenarios (see the Appendix for the Spanish version). One translator fluent in Spanish and English translated the English version of the scenarios into Spanish. A separate translator fluent in Spanish and English translated the scenarios back from Spanish into English.Footnote 13 There were no substantial disagreements between translators and there were few discrepancies between translations. All discrepancies were negotiated until both translators agreed. Participants also received a Spanish version of the free will questions. Participants could rate their level of agreement from 1 (strongly disagree) to 7 (strongly agree) to each of the three prompts. Participants also received the Spanish version of the Ten Item Personality Inventory (Gosling et al., 2003).

Responses to free will questions had strong internal consistency (Cronbach’s Alpha = .89). To simplify analyses, a compatibilist composite score (mean of response to 1–3) was calculated. To test for differences between Determinism High Affect and Determinism Low Affect, an analysis of variance (ANOVA) was conducted with the compatibilist composite score as the dependent variable and condition as the independent variable. Consistent with the meta-analysis discussed above (A. Feltz & Cova, 2014), there was not a significant difference between Determinism High Affect (M = 5.6, SD = 1.45) and Determinism Low Affect (M = 5.75, SD = 1.79) (F < 1, ηp2 = .01). To increase statistical power, Determinism High Affect and Determinism Low Affect were analyzed together to estimate the relation of compatibilist intuitions with the global personality trait extraversion. As predicted, there was a significant, positive correlation between the compatibilist composite score and extraversion, r (71) = .28, p = .02. Extraversion was the only personality trait significantly correlated with compatibilist judgments (rs between −.12 and .18, ps > .14).

Results from the first Spanish language experiment were consistent with results from previous studies using English speakers and provided evidence that the new materials were reliable Spanish language instruments. First, people had overall compatibilist friendly judgments. Second, there was no reliable difference between the high and low affect versions. Third, and importantly, the global, heritable personality trait extraversion predicted compatibilist judgments.

While the consistency of the Spanish language results was predicted based on past theory and evidence, it is still desirable to replicate and extend these findings. The second experiment also assessed the extent to which Spanish speakers could discriminate between determined and fated actions. Specifically, in the second new experiment, 141 participants were recruited from Amazon’s Mechanical Turk using the same Spanish language recruitment materials. Participants were excluded because they requested that their answers not be used (N = 6) or did not complete the survey (N = 13). Forty-seven participants were excluded for failing at least one of the Spanish comprehension questions. Forty-two (56%) identified as male.

The same Spanish language determinism scenarios were used in a new study. In addition, participants received a Spanish version of a scenario that described fatalism (the Book scenario from earlier in this chapter). As in the first experiment, one coder fluent in Spanish and English translated the English version of Book into Spanish. A separate coder fluent in Spanish and English translated the Spanish version back into English (see the Appendix for Spanish language versions). There were only minor disagreements about translations that were resolved with discussion. Participants also received the Spanish language version of the free will questions. Two groups of participants were randomly assigned to either the high affect or low affect conditions. Those in the high affect condition received the Determinism High Affect and Book High Affect (N = 38), counterbalanced for order. A separate group received the Determinism Low Affect and Book Low Affect (N = 37), counterbalanced for order. Participants received the appropriate versions of the free will questions. Participants also responded to the Spanish version of the Ten Item Personality Inventory.

Analyses of the second Spanish language study revealed strong internal consistency of judgments about the determinism (Cronbach’s alpha = .90) and the fatalism scenarios (Cronbach’s alpha = .91). Compatibilism and Fatalism composite scores were calculated (mean of responses to 1–3). Replicating previous research, a mixed-model repeated measures ANOVA with order and affect as between participant factors and Compatibilism and Fatalism composites scores as within participant factors revealed a large, significant difference between Fatalism (M = 4.1, SD = 2.21) and Compatibilism composite scores (M = 5.59, SD = 1.72), F (1, 71) = 32.22, p < .001, ηp2 = 32. Neither affect (F < 1) nor order (F < 1) interacted with judgments. To increase statistical power, responses to high and low affect scenarios were combined for subsequent analyses. Extraversion was again related to compatibilist judgments, r (75) = .30, p = .008. Extraversion was the only member of the Big Five reliably related to compatibilist judgments (rs < .18, ps > .13). Somewhat surprisingly, extraversion was also related to the Fatalism composite score r (75) = .37, p = .001. Openness to experiences was also related to the Fatalism composite score r (75) = .31, p = .007. None of the other three Big Five personality traits were related to the Fatalism composite score (rs < .06, ps > .6). To test whether extraversion and openness to experience were independent predictors of agreement with the Fatalism composite score, a multiple linear regression with extraversion and openness to experience as predictor variables of the Fatalism composite score was constructed. The full model was a significant predictor of the Fatalism composite score: F (2, 72) = 8.07, p = .001, R2 = .18. Both extraversion (β = .32, t (72) = 2.78, p = .007) and openness to experience (β = .22, t (72) = 2.02, p = .05) were independent predictors. Since the relations of personality with the Fatalism composite score were not predicted, they should be interpreted with caution even though the correlations and regression model for extraversion remained significant after a conservative Bonferroni correction (p = .01).

Results from these two new Spanish language experiments suggested that the Spanish versions of Determinism and Book assessments accorded with studies using English instruments. Once again, most people had compatibilist friendly intuitions and extraversion predicted compatibilist judgments. Overall, these three studies indicate that extraversion is likely to be a robust predictor of compatibilist judgments across many different languages and cultures.

The Importance of the Individual

So far, we have reviewed a large array of studies suggesting that personality predicts some intuitions about free will and moral responsibility. The evidence we have presented cautions against any sweeping explanation of intuitions about freedom and moral responsibility that does not take into account individual differences. These studies serve as a fine contemporary illustration of why one should not only use overall means to infer actual cognitive processes (Estes, 1956; Molenaar & Campbell, 2009). To illustrate, we will use the affective performance error model to demonstrate the problems associated with not taking into account individual differences when generating models or accounts of the proximal cognitive process involved in philosophically relevant (or other) intuitions. The affective performance error model holds that affective responses generate more compatibilist intuitions. That is, on one natural reading of the affective performance error model, the same individual can on one occasion have compatibilist intuitions, yet on another occasion can have incompatibilist intuitions as a function of the affect.Footnote 14 The existence of individual differences suggests that folk intuitions about freedom and moral responsibility are likely to be much more stable, yet varied, than this model suggests. To hold that “the folk,” as a monolithic entity, engage in an affective performance error would thereby not be accurate. Introverts (or some other identifiable subgroup) may be altogether unaffected by the affective content of scenarios, whereas extraverts (or some other identifiable subgroup) may be influenced by the affective content making their already compatibilist intuitions even stronger. Taking the overall mean response of extraverts and introverts could give the impression that affect influences people overall—or that affect doesn’t influence people very much. But that would be inaccurate or incomplete because only one group is reliably influenced by affect. More nuanced accounts are therefore required to capture the variability or boundaries in the processes that generate these intuitions, which are required to have a descriptively accurate understanding of folk intuitions about free will and moral responsibility (or other philosophically relevant intuitions).

To reiterate, one reason why extraversion might be related to compatibilist judgments is that extraverts, compared to introverts, interpret scenarios differently, enjoy social interactions, are more socially motivated, and less tightly regulate their emotional reactions. For these reasons, extraverts may be more likely to hold a person morally responsible especially for bad actions with high affective content in deterministic scenarios. If extraverts have these tendencies, then there is a straightforward prediction about affect: to the extent that the affect is increased, extraverts should be disproportionately influenced by affect compared to introverts. Introverts’ judgments should remain relatively stable across scenarios that vary affect whereas extraverts’ compatibilist intuitions should be stronger. In other words, extraversion should moderate the relation of affect to free will and moral responsibility judgments.

To test this hypothesis, we conducted a preliminary experiment. One hundred and forty-five participants were recruited from Amazon’s Mechanical Turk. Four participants were excluded from analyses for not completing the survey or for requesting that their answers not be used. Fourteen participants were excluded from analyses for failing a comprehension question. Sixty-five (51%) participants identified as male. Ages ranged from 18–65, M = 31.92, SD = 12.01.

We assigned participants to only one of the Low or High Affect Determinism cases. We then gave participants the free will questions along with a standard comprehension question. Participants then completed the Ten Item Personality Inventory (Gosling et al., 2003). Basic demographic information was collected after completing the Ten Item Personality Inventory.

Responses to the free will questions showed strong internal consistency (Cronbach’s α = .93), so a composite free will score was calculated to simplify analyses (mean of answers to 1–3). Replicating Nichols and Knobe’s results, an analysis of variance showed that people given the high affect scenario had stronger compatibilist judgments (M = 4.53, SD = 2.11) than those given the low affect scenario (M = 3.7, SD = 2.36) F (1, 125) = 4.29, p = .04, ηp2 = .03. However, consistent with the previous meta-analytic results, the effect size was small (about 1% of the variance) (A. Feltz & Cova, 2014). Additionally, replicating previous studies, extraversion was associated with compatibilists responses in the high affect case (N = 65), r = .32, p = .009; however, extraversion had no reliable relation to judgments in the low affect case (N = 62), r = −.06, p = .65.

Our main concern was whether extraversion moderated or interacted with the relation of affect and compatibilist judgments. An interaction in the statistical sense implies non-linear relations like 1 + 1 = 3 (e.g., dieting may help you lose 5lbs, exercise may help you lose 5lbs but if you diet and exercise you may lose 7lbs or 15lbs). In short, moderation and statistical interaction modeling is used when estimating the extent to which the whole is more (or less) than the sum of its parts. Because the correlations in this study suggested moderation (i.e., correlation in one but not the other case), a hierarchical linear regression was conducted to formally estimate moderation. Extraversion scores were centered and an interaction term was calculated (extraversion score * high/low affect). Extraversion, high/low affect, and the interaction term were entered in that order in different steps of a linear regression. Extraversion (b = .93, SEb = .41, β = 1.39, t = 2.27, p = .03) and high/low affect ((b = .81, SEb = .39, β = .18, t = 2.07, p = .04) were both significantly associated with compatibilist judgments in the regression. Crucially for our purposes, the interaction was also statistically significant (b = .24, SEb = .12, β = 1.28, t = 2.1, p = .04; R2change = .03, F (1, 123) = 4.27, p = .04). Simple slopes were tested, and low extraversion (−1 standard deviation) was not associated with compatibilist judgments (b = .01, SEb = .55, t = .02, p = .98, 95% CI = −1.08 – 1.11). Moderate (mean) (b = −.81, SEb = .39, t = 2.07, p = .04, 95% CI −1.58 – −.03) and high (+1 standard deviation) (b = −1.63, SEb = .55, t = 2.95, p = .003, 95% CI = −2.73 – −0.54) extraversion were related to compatibilist judgments. Indeed, those who were the most strongly extraverted had the strongest compatibilist intuitions in high affect and were the most influenced by the change in affective content.

To illustrate, Fig. 2.4 visually represents the data. For simplicity, the graphs invites you to imagine that there are three groups of people. There is the person who is of “average” extraversion (the solid line). Then there are two other groups of people who are very high in extraversion (the dotted line), and those who are very low in extraversion (the dashed line). For the time being, ignore the “mean” extraversion (the solid line) group and just look at the two extreme groups. Here, we see there is a pronounced difference with the way that extraversion influences those two groups of people. Compared to introverts, those who are extraverted are much more likely to judge a person free and morally responsible in the high affect case compared to the low affect case. That, in essence, is the nature of the interaction. However, now imagine what the graph would look like if you averaged to two extreme groups. If you imagined that the average would look like the solid black line, then you are right. If you average all responses, you will find a very small overall effect even though it is a fiction produced by averaging differences in some identifiable groups (e.g., those high in extraversion) who are influenced by affect and some that were not (e.g., those low in extraversion).

Fig. 2.4
A multiline graph plots agreement versus extraversion. The high affect line plots an increasing curve from (4, 3.8) to (11, 5.2). The low affect line plots an increasing curve from (4, 3.8) to (11, 4.5). The mean line plots a decreasing curve from (4, 3.8) to (11, 3.55). Data are estimated.

Personality moderating judgments of free will and moral responsibility between high and low affect cases

These results support our prediction concerning why the effect of affect on people’s free will and moral responsibility judgments is typically small. Only some people are influenced by affect whereas others are not. Those who are high in the personality trait extraversion are relatively strongly influenced by the affective content of the scenarios whereas introverts are not influenced by the affect (if anything, there is a non-statistically significant numerical shift in the opposite direction). When these groups are combined, introverts mute the effect of affect. The result is an overall small effect that is sometimes difficult to detect with overall mean scores. As such, any model that does not take into account individual differences risks modeling a fictitious “average” person. In this case, “the average” does not seem to accurately represent any of the actual subgroups of respondents, as many people tend to have more (or less) polarized sets of intuitions as compared to the average. This is like what you might find by averaging people’s responses on surveys about their political orientation. The “average” person may be politically moderate. However, most people exist closer to political extremes. Only focusing on the “average” thus distorts or neglects people closer to the extremes, and so offers a distorted or otherwise inaccurate description of response patterns.

Conclusion

This chapter has reviewed a diverse body of scientific data indicating that personality predicts intuitions about freedom and moral responsibility. The relation between extraversion and compatibilist judgments is found in different labs, using different materials, with different response options, measured cross-culturally with diverse samples of people from various backgrounds who speak different languages. Across all studies, research consistently finds that personality predicts free will and moral responsibility intuitions about the compatibility question, manipulation, and some fated actions.

These results are not only empirically interesting, they also have some philosophical bite. One theoretical assumption is that intuitions are invariant (i.e., they do not change much from place to place, time to time, or person to person) (Knobe & Doris, 2010). There are at least three kinds of variance. Inter-cultural variance occurs when members of different cultures (e.g., Easterners and Westerners) have different intuitions. Intra-cultural variance occurs when individuals of the same culture have different intuitions (e.g., extraverts in America have different intuitions than introverts in America). Inter-temporal variance occurs when the same individual has different intuitions at Time 1 and Time 2. These three types of variances are logically independent. They could all be true, they could all be false, or some may be true while some may be false. Do the studies presented in this chapter inform what types of variability there is with free will and moral responsibility intuitions? To more precisely answer this question, we’ll concentrate on variability associated with the compatibility question.

Take inter-cultural variability. Quite a lot has been made of inter-cultural variability in people’s intuitions about a variety of subjects. However, it appears that there are some culturally universal intuitions about freedom and moral responsibility. Sarkissian et al. (2010) found that there was not much inter-cultural variability when the compatibility question was framed abstractly. Most people across cultures had incompatibilist friendly intuitions. Schulz et al. (2011) found that intuitions about concretely described individuals appeared to be compatibilist in a German-speaking European sample. These two studies suggest that the abstract/concrete difference may exist in different cultures. Consequently, these data suggest cross-cultural stability for at least some prominent effects in the experimental philosophy of free will.Footnote 15 Admittedly, there is a relatively small amount of data about inter-culture reliability of personality’s relation to free will judgments. But if future work resembles past work, we should continue to see these relations cross-culturally.

While there appears to be some inter-cultural stability about the compatibility question, the same cannot be said about intra-cultural stability. In some instances, there is substantial divergence in intuitions of people within the same culture. For example, the relation of extraversion with compatibilist intuitions in Spanish, English, and German-speaking samples suggests that there is consistent intra-cultural variance in intuitions about the compatibility question. The inter-cultural stability and intra-cultural variability associated with personality is to be expected. Recent studies suggest that the members of the Big Five personality traits are present across almost all cultures and have roughly the same distribution, especially in Western cultures (Schmitt et al., 2007). Because extraversion is associated with many compatibilist intuitions and extraversion is present in many cultures, we should expect that (a) intuitions about the compatibility question are stable cross-culturally and (b) that within the culture, personality would predict intuitions about the compatibility question.

The studies in this chapter also reveal at least some short-term inter-temporal stability. When presented with both High and Low Affect Determinism scenarios, people tend to have incompatibilist intuitions about both scenarios and the short-term stability of judgments between these scenarios is high (r = .75) (A. Feltz & Cokely, 2019). The relation to global personality traits bolsters the inter-temporal stability of intuitions about freedom and moral responsibility. While there is some evidence of personality traits change somewhat over the course of life, especially for younger people, after age 30 there is relatively little change in personality traits relative to their own cohort (McCrae, 2002). Differences in personality also tend to be relatively stable even when they change (e.g., older adults will tend to be moderately more conscientious than younger adults; however, someone who is moderately conscientious will stay that way most of their life relative to people of the same age (Ashton, 2013)). Moreover, many of global or general personality traits (e.g., extraversion) are strongly heritable (Bouchard & Loehlin, 2001; Jang, Livesley, Angleitner, Riemann, & Vernon, 2002; Luo, Kranzler, Zuo, Wang, & Gelernter, 2007; Spinath & Johnson, 2011; Wilt & Revelle, 2009). Some of the estimates suggest that the heritability of personality traits (i.e., the amount of variance in a population that is attributable to genes) is about 50% (Bouchard & McGue, 2003). This means that not only are similar intuitions about the compatibility question likely to persist over one’s life, one may be quite likely to pass on the tendencies to have those intuitions to the next generation. In the light of evidence that even experts show similar patterns of bias (see Chap. 5), disagreement about the compatibility question seems very likely to be persistent and trans-generational across cultures.

Of course, the personality traits associated with free will intuitions could be culturally variable (e.g., personality and culture could interact). For example, East Asians tend to be less extraverted than people in other parts of the world (Schmitt et al., 2007). This would suggest that there should be fewer individuals in that part of the world who respond that one could be free and morally responsible for concretely described compatibility questions. However, the effect of culture on the relation between personality and compatibilist judgments is likely to be small since there is an overall modest effect of culture on extraversion (about 3% of the variance) (Schmitt et al., 2007). Future research is needed to determine if, how, or where personality and culture interact to generate intuitions about the compatibility question.

Taken altogether, the evidence and statistical models we have reviewed strongly suggest to us that intuitions about free will and moral responsibility are temporally stable, pervasive (inter-culturally stable), and likely to be very similar around the world (intra-cultural variability). For some people, judgments about freedom and moral responsibility are robust to a number of different threats to freedom and moral responsibility such as determinism, moment-by-moment manipulation, fate, or being compelled to act by a neurological condition (De Brigard, Mandelbaum, & Ripley, 2009). However, others are sensitive to these threats to free will. Consequently, there is a spectrum of intuitions about freedom and moral responsibility that are a function of a variety of factors. Nevertheless, many of these intuitions are associated with heritable personality traits that are known to be largely stable across cultures and lifespan.