The tendency to favor their ingroup develops quickly in young children, increasing up to about six years of age, and almost immediately begins to influence their behavior (Aboud, 2003; Aboud & Amato, 2001). Young children show greater liking for peers of their own sex and race and typically play with same-sex others after the age of three. And there is a norm that we should favor our ingroups: people like people who express ingroup favoritism better than those who are more egalitarian (Castelli & Carraro, 2010). Amazingly, even infants as young as nine months old prefer those who treat similar others well and dissimilar others poorly (Hamlin, Mahajan, Liberman, & Wynn, 2013). Ingroup favoritism is found for many different types of social groups, in many different settings, on many different dimensions, and in many different cultures (Bennett et al., 2004; Pinter & Greenwald, 2011). Ingroup favoritism also occurs on trait ratings, such that ingroup members are rated as having more positive characteristics than are outgroup members (Hewstone, 1990). People also take credit for the successes of other ingroup members, remember more positive than negative information about ingroups, are more critical of the performance of outgroup than of ingroup members, and believe that their own groups are less prejudiced than are outgroups (Shelton & Richeson, 2005).
People also talk differently about their ingroups than their outgroups, such that they describe the ingroup and its members as having broad positive traits (“We are generous and friendly”) but describe negative ingroup behaviors in terms of the specific behaviors of single group members (“Our group member, Bill, hit someone”) (Maass & Arcuri, 1996; Maass, Ceccarielli, & Rudin, 1996; von Hippel, Sekaquaptewa, & Vargas, 1997). These actions allow us to spread positive characteristics to all members of our ingroup but reserve negative aspects for individual group members, thereby protecting the group’s image.
People also make trait attributions in ways that benefit their ingroups, just as they make trait attributions that benefit themselves. As we saw in Perceiving Others, this general tendency, known as the group-serving bias (or ultimate attribution error), results in the tendency for each of the competing groups to perceive the other group extremely and unrealistically negatively (Hewstone, 1990). When an ingroup member engages in a positive behavior, we tend to see it as a stable internal characteristic of the group as a whole. Similarly, negative behaviors on the part of the outgroup are seen as caused by stable negative group characteristics. On the other hand, negative behaviors from the ingroup and positive behaviors from the outgroup are more likely to be seen as caused by temporary situational variables or by behaviors of specific individuals and are less likely to be attributed to the group.