Social Selection for Human Altruism
There are diverse usages of the term “social selection.” It has been (misguidedly, in our view) theorized as an alternative to sexual selection theory (Roughgarden 2012). In contrast, West-Eberhard (1979) considered it useful to distinguish between sexual selection (produced by mate choice and social competition for mates) and social selection (produced by social competition for resources rather than social competition directly for mates), viewing them as two complementary forms of natural selection related to intraspecific social competition. Others have also pointed out that sexual selection can be conceptualized as a subset of social selection (Lyon and Montgomerie 2012). The more general concept of social selection seems to help better explain some traits related to female competition for ecological resources better than traditional sexual selection theory (Tobias et al. 2012). Distinguishing the more general concept of social selection from sexual selection seems to help explain some traits, particularly traits related to female competition.
Social competition directly for ecological resources may select for diverse strategies for acquiring those resources including the use of cooperative interactions. Below, we consider how social selection may have adaptively shaped human personalities for displays of value as a social partner and traits that promote cooperative, rule-compliant, and altruistic behavior in some individuals more than others. Increased social competition for resources may favor preferences for choosing social partners who display these potentially valuable social traits, important in successfully acquiring resources (Nesse 2007).
Runaway Social Selection for Extreme Altruism
Nesse (2007) argued that runaway social selection, driven by competition to be chosen as a social partner in mutually beneficial interactions, could explain the evolution of various extreme human traits including altruism, cooperation, and our moral capacities. Accordingly, just as potential mates compete by displaying traits that influence mate choice, potential social partners compete by displaying traits that influence social partner choice. Potential partners vary in resources and reliability of providing selective benefits (i.e., partner value). Displays of and preferences for extreme partner value are naturally associated within social interactions and “can result in runaway social selection increasing both traits to extremes,” even decreasing other traits/characteristics related to individual fitness. Our own social partner and mate choices for desirable personality traits may have “domesticated” us, resulting in extreme eagerness to please others, high altruism, lower aggression, and moral commitments.
Simon (1990) described an alternative model of intense social selection for similar traits such as “docility” – readiness to accept social instruction, social influence, and to conform to norms – and costly altruism, even if providing that altruism had a net fitness cost to individuals that was “beyond support from expected reciprocity or social enforcement” (i.e., beyond benefits of partner choice or punishment of cheaters). Both models of these social selection seem to predict particular traits (e.g., docility, rule-compliance, guilt, shame, empathy) closely associated with agreeableness and conscientiousness are strongly socially selected.
Controversially, researchers report that the big five personality traits intercorrelate somewhat. A higher-order trait, known as the GFP (general factor of personality), includes statistical variance from each of the “big five.” High GFP scorers report high Openness, Conscientiousness, Extraversion, Agreeableness, and low Neuroticism. Consistent with social selection theories, Rushton and Irwing (2011) suggested the GFP was, perhaps, selected for altruism and socially desirable behavior. The GFP has also been empirically associated with higher reported strength of rule-compliance or rule-governance (Gladden et al. 2012), defined as control of behavior by antecedent verbal instructions and, so, relates closely to docility and compliance to social norms. Rule-compliance fully mediated negatives relations between the GFP and delinquent behaviors.
Altruism as a Socially Selected Costly Signal
Zahavi and Zahavi (1997) argued altruistic behavior directly benefits altruists because they gain social prestige. They explain altruistic behavior as a costly, honest signal of individual quality. Those that can demonstrate superior levels of altruism gain in terms of social prestige, ultimately gaining reproductive advantages. As evidence for their altruism as a handicap to gain prestige theory view (and contrary to predictions from reciprocal altruism theory), they explain that avian babblers “compete with one another for the ‘right’ to be altruistic,” and, rather than “expect” partner reciprocation, babblers prevent each other from doing their share. They suggest altruistic acts could be considered substitute threats because, based on their theory, altruistic acts function to gain competitively limited resources (status).
Consistent with a costly signaling function of altruism, social selection may favor individuals that successfully compete for social prestige by providing altruism. When altruistic behavior is viewed as a costly signal of some aspects of phenotypic quality (or superiority), we should expect social selection to lead people to “show off” (perhaps without awareness) more altruism than others can in order to enhance one’s social prestige. Supporting this, Berczkei et al. (2010) found when volunteering publicly, participants chose costlier actions, which increased social prestige among observers, but chose less costly activities when volunteering anonymously. Displaying generosity, fair moral reasoning, and/or moral outrage in response to violations could also potentially serve as competitive signals of one’s value and trustworthiness as a social partner within a group.
Stable Social Conditions, Associated with Slow Life History Strategies, may Promote Socially Selected Displays and Preferences of Altruism
Figueredo et al. (2015) argued that social selection may be one of several (multi-level and sometimes opposing) evolutionary forces jointly shaping individual differences in evolved life history strategies. Because “slow” life history strategies (in contrast to “fast” life history strategies) should be favored under stable and controllable social and ecological conditions where long-term social relationships and altruism are potentially more beneficial, slow life history strategists should be more adapted to “invest in” stable social bonds, attachments, and stable social relationships. Thus, slow life history strategists should be expected to more intensely compete for opportunities for mutually beneficial social interactions and/or to gain social prestige by displaying costly altruism (Zahavi and Zahavi 1997), moral commitments, and trustworthiness.
Consistent with the view that stable social environments promote altruism, Wilson et al. (2009) reported that, across Binghamton, NY, “prosocial” individuals receive multiple forms of social support while living in neighborhoods with larger numbers of altruistic residents, who may naturally “find” and associate with one another. From a life history theory perspective, these clusters of prosocial individuals offer a stable and supportive social environment that facilitates and favors clusters of slow LH strategists mutualistically interacting. In contrast, clusters of fewer (available) altruistic partners are inconsistent with investing in mutualistic social strategies for acquiring resources and favor fast LH strategies, opportunistically taking more immediate benefits/resources when available.
Social selection encompasses all forms intraspecies social competition over any evolutionarily important resource. Social competition through partner choice, costly displays of partner value, and the nonrandom formation of cooperative social groups could have strongly shaped human personalities over evolutionary time, perhaps including favoring higher levels of the general factor of personality (GFP) and slow life history strategies. Social selection for altruistic personalities may be particularly strong under stable and controllable socioecological conditions where altruistic interactions may potentially have higher payoffs and where “runaway sexual selection” (Nesse 2007) could become established. However, no single evolutionary selective pressure is likely to account for human altruism across situations.
- Figueredo, A. J., Patch, E. A., & Ceballos, C. E. G. (2015). A life history approach to the dynamics of social selection. In Evolutionary perspectives on social psychology (pp. 363–372). NY: SpringerGoogle Scholar
- Gladden, P. R., Furrow, D., & Jacobs, W. J. (2012). Rule governance mediates relations between general factor of personality and delinquency. Human Behavior and Evolution Society Conference. Albuquerque, New Mexico. June 2012. Poster.Google Scholar
- Rushton, J. P., & Irwing, P. (2011). The general factor of personality. In T. Chamorro-Premuzic, S. von Stumm, & A. Furnham (Eds.), The Wiley-Blackwell handbook of individual differences (pp. 132–161). Oxford, UK: Wiley-Blackwell.Google Scholar
- Tobias, J. A., Montgomerie, R., & Lyon, B. E. (2012). The evolution of female ornaments and weaponry: Social selection, sexual selection and ecological competition. Philosophical Transactions of the Royal Society of London B: Biological Sciences, 367(1600), 2274–2293.CrossRefPubMedPubMedCentralGoogle Scholar
- West-Eberhard, M. J. (1979). Sexual selection, social competition, and evolution. Proceedings of the American Philosophical Society, 123(4), 222–234.Google Scholar
- Zahavi, A., & Zahavi, A. (1997). The handicap principle: A missing piece of Darwin’s puzzle. Oxford University Press, Oxford.Google Scholar