Encyclopedia of Evolutionary Psychological Science

Living Edition
| Editors: Todd K. Shackelford, Viviana A. Weekes-Shackelford

Benefit Group Relative to Other Groups

  • Alexander ShkurkoEmail author
Living reference work entry
DOI: https://doi.org/10.1007/978-3-319-16999-6_1630-1



Behavior and decisions in favor of a group with which an individual affiliates


Living in groups implies that people develop attitudes and behaviors based on group membership. Identifying different groups is associated with asymmetrical reactions toward their members. Such asymmetries exist in various types of reactions: cognitive (biases), affective and attitudinal (prejudice), and behavioral (discrimination). Sometimes, researchers consider them as parts of the same process or use these terms as synonyms. However, most contemporary researchers agree that it is important to differentiate between prejudicial attitude and discriminatory behavior. At the behavioral level, people tend to allocate resources and make other decisions benefiting their group and prefer cooperation with the members of their group. Intergroup discrimination is thought to underlie variety of important social problems ranging from discrimination in labor or education to wars and genocide.

Ingroup Favoritism in Animals

Evolutionary origin of ingroup-benefiting behavior is supported by many facts of similar reactions in various species. Ingroup behavioral preference is common not only for primates but also for other animals such as dolphins, elephants, meerkats, lizards, birds, ants, etc., and some researchers even use similar terminology to describe behavior of microbes (Strassmann et al. 2011). In animal studies, ingroup favoritism is typically understood as a form of cooperative behavior. Typical examples of cooperation include territory defense or acquiring, joint struggle for food or mates, and communal nesting, although some researchers also include more specific forms of behavior such as grooming or interactions during water search (Masuda and Fu 2015). Importantly, animal studies show that such cooperation is not necessarily based on kinship but can be based on more complex affiliations and social structures.

Ingroup Favoritism in Humans

Within human societies, benefiting one’s own group is much more diverse and complicated, often moderated by various factors such as social status, normative beliefs, or multiple identities. One of the first experimental studies demonstrating ingroup-favoring behavior was conducted in the 1950s by a group of psychologists headed by M. Sherif. They used a field experiment in a summer camp, by arbitrary dividing boys into two groups and fostering competition between them (Sherif et al. 1961). The group membership manipulation was successful, and the members of each group easily formed both positive attitude toward ingroup and negative attitude toward outgroup, with corresponding behavioral outcomes. Later, J. Tajfel et al. (1971), using laboratory experiments, confirmed that differential reactions can be the result of absolutely arbitrary, temporary, and contextual group memberships imposed by an experimenter – what is currently known as a “minimal group.” In these experiments, participants were divided into two groups on the basis of irrelevant criteria (e.g., perceived accuracy of simple task performing or preference for Klee or Kandinsky paintings) and had to allocate resources between the members of the two groups. The study showed that participants not only tended to benefit their own group but also that they strived to maximize the difference in rewards between groups rather than maximizing ingroup profit. The experiments using “minimal-group paradigm” allowed to suppose that the tendency to make decisions in favor of one’s own group is a direct consequence of self-categorization, i.e., identifying oneself with a particular social group or category. This means that the tendency to benefit ingroup is present even when group members don’t know each other and don’t interact and don’t have personal benefits from the discriminating behavior.

Later, numerous psychological studies demonstrate intergroup discrimination using various methods and situations. The most common laboratory experiments use two-player games:
  • Allocation matrixes: participants allocate rewards and/or penalties between ingroup and outgroup members.

  • Dictator games: participants play a role of a “dictator” freely distributing rewards between him-/herself and a different player who can be ingroup or outgroup member.

  • Trust games: Participants play a role of an “investor” receiving endowment which can be partially or in a whole transferred to a trustee (ingroup or outgroup), who can return any sum from the reward multiplied by an experimenter.

  • Social dilemmas such as prisoner’s dilemma, when two participants simultaneously decide what share of their endowment to give to each other (Balliet et al. 2014).

In addition to laboratory experiments, psychologists conduct field studies of discriminating behavior using such methods as observation of helping behavior, hiring and housing audits, studies of policy profiling, and opinion surveys (Greenwald and Pettigrew 2014).

Most of the studies supported the view that ingroup favoritism is a common strategy underlying intergroup relation. Comparing many experimental studies using various tasks and conditions, psychologists from the Netherlands concluded that discriminating in favor of one’s group is the most frequent strategy although some studies show preference for outgroup members. Psychological studies of ingroup favoritism cover both artificial, experimentally created and natural groups based on race, ethnicity, nationality, political and organizational affiliation, support for a sport team, and others. In general, discriminatory behavior is typical for any types of group membership (Balliet et al. 2014). At the same time, other factors can affect nuances of group-based discrimination. For example, expectation of future interaction makes discriminating behavior favoring ingroup member more probable, although mere categorization is often sufficient for ingroup favoritism. The existence of common knowledge about group membership also fosters ingroup favoritism showing that individuals care about their reputation necessary for living in a group. Social status considerations and normative beliefs can also affect the tendency to favor one’s group.

Importantly, discriminating behavior can result from two distinct types of prejudice: positive attitudes toward ingroup members and negative attitude or hostility toward outgroup members. Although they may seem to be two sides of the same process, the contemporary social psychology sees them as distinct and stresses that discrimination can result from favoring ingroup without hostility to outgroup (Greenwald and Pettigrew 2014). Moreover, identifying oneself with particular group is sufficient for discriminatory behavior and doesn’t need a clearly defined outgroup (Balliet et al. 2014).

Explanations of Ingroup Favoritism

In explaining the origins and mechanisms of ingroup favoritism, a number of theories have been proposed, mostly within social psychology and evolutionary approaches. In social psychology, ingroup favoritism is explained by social identity and self-categorization theories, balance identity theory, system justification theory, social dominance theory, uncertainty reduction theory, bounded generalized reciprocity theory, and others (Greenwald and Pettigrew 2014; Everett et al. 2015). Evolutionary approaches are generally based on mathematical models, applied to animal populations, and include direct reciprocity, indirect reciprocity, tag-based cooperation, group selection, spatial structure, and other models (Masuda and Fu 2015). Less recognized in social psychology are theories deriving discrimination from the society’s structural and normative organization (Greenwald and Pettigrew 2014).

Despite important nuances between the theories, the key discussion in contemporary psychological science is between theories deriving ingroup-favoring behavior from social identity and those focusing on actual and future interactions (Balliet et al. 2014; Everett et al. 2015). Identity-based approaches derive ingroup favoritism from the self-categorization process and the universal motivation for positive self-esteem. If a clear distinction between ingroup and outgroup is present, whatever is the rationale for such a distinction, individuals tend to perceive themselves and others in terms of their group membership (depersonalization). When individuals perceive themselves this way, they may consider ingroup members as part of themselves, and their motivation for self-esteem or positive evaluation can project onto ingroup members. Favoring ingroup increases its power and/or superiority over outgroup, thus increasing individual’s self-regard. Interaction-based approaches, on the contrary, consider ingroup favoritism as a more rational, belief-based behavior. Benefiting people having something in common with an individual can be a rational strategy when the future interactions with them are more probable than with outgroup members. Expectation of future interactions and direct or indirect reciprocity can lead to ingroup-favoring behavior.

At present, it is difficult to conclude which of the existing theories and approaches better explain complex and multifaceted discriminatory behaviors in modern societies. Most methods and studies have important limitations associated with measurement procedures, boundary conditions, representativeness of samples, lack of cross-cultural comparisons, etc. A large-scale comparison of psychological studies conducted by the Netherland psychologists led them to the conclusion that evolutionary explanations are generally more appropriate than the self-categorization theory, because they correctly predict that favoring ingroup doesn’t need the clearly defined opposition between ingroup and outgroup (Balliet et al. 2014). However, such a comparison also has methodological limitations and doesn’t cover studies not based on laboratory experiments.

Last decade, the development of social and cognitive neuroscience allowed a better understanding of neural mechanisms underlying ingroup favoritism. Some studies showed that even the “minimal-group” membership leads to different neural reactions to ingroup and outgroup members in a way more consistent with identity-based rather than interaction-based approaches. For example, costly helping to ingroup members involves greater activation in anterior insula, a brain region associated with empathy (Hein et al. 2010). Another study showed that ingroup-benefiting allocation of rewards was associated with activity in the medial prefrontal cortex and anterior cingulate cortex, regions associated with self-processing and thus probably indicating that in these cases participants perceived ingroup members as part of themselves (Volz et al. 2009). However, these findings don’t mean that the ingroup-favoring decisions should be necessarily determined by the only neural mechanism. Indeed, a recent study showed that reward-related neural processes can support trust and cooperation with ingroup members, whereas trust and cooperation with outgroup members involve neural systems responsible for control functions (Hughes et al. 2017).


Ingroup favoritism and discrimination against other group are by no means a fundamental aspect of human social behavior underlying many important social phenomena, both positive (e.g., teamwork) and negative (e.g., wars and xenophobia). The complexity of social interactions, beliefs, and identities may partially explain why so many theories of discrimination based on group membership exist and why no one of them seems to be sufficient. Studies show the diversity of human reactions toward the social groups indicating that probably the search of a single mechanism underlying them is a wrong strategy. Instead, a more integrative approaches, focusing on both identity construction and expectations of reciprocity, taking into account such factors as cultural norms or social status, is supposed to be the main direction of future research (Everett et al. 2015).



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Authors and Affiliations

  1. 1.Independent ResearcherUlyanovskRussia

Section editors and affiliations

  • Kevin Beaver
    • 1
  1. 1.Florida State UniversityTallahasseeUSA