Copy the In-group: Group Membership Trumps Perceived Reliability, Warmth, and Competence in a Social-Learning Task

Surprisingly little is known about how social groups influence social learning. Although several studies have shown that people prefer to copy in-group members, these studies have failed to resolve whether group membership genuinely affects who is copied or whether group membership merely correlates with other known factors, such as similarity and familiarity. Using the minimal-group paradigm, we disentangled these effects in an online social-learning game. In a sample of 540 adults, we found a robust in-group-copying bias that (a) was bolstered by a preference for observing in-group members; (b) overrode perceived reliability, warmth, and competence; (c) grew stronger when social information was scarce; and (d) even caused cultural divergence between intermixed groups. These results suggest that people genuinely employ a copy-the-in-group social-learning strategy, which could help explain how inefficient behaviors spread through social learning and how humans maintain the cultural diversity needed for cumulative cultural evolution.

Inequality in the minimal group paradigm: How relative wealth and its justification influence ingroup bias

This article details a registered report for a well-powered (N = 1500) experiment examining the influence of wealth inequality between groups on ingroup bias, as well as the potential moderating role of justification for the wealth distribution. Using the Minimal Group Paradigm, in which participants are assigned to groups with anonymous others and asked to allocate resources to ingroup or outgroup members, we randomly assigned participants to a relatively disadvantaged or a relatively advantaged group. Group assignments were ostensibly based on chance (weak justification), performance on a financial decision-making task (strong justification), or an ambiguous combination of the two (ambiguous justification). As expected, we found evidence for an inequity aversion hypothesis, with disadvantaged participants displaying heightened ingroup bias compared to their advantaged counterparts. Interestingly, however, our predictions regarding the moderating role of justification were not supported, with disadvantaged participants displaying the highest ingroup bias when the inequality was ambiguously justified. We discuss implications of these results for understanding the causal factors underlying ingroup bias.

The dynamic emergence of minimal groups

The minimal group paradigm has consistently shown that people will discriminate to favor their own group over an out-group, even when both groups are created arbitrarily by an experimenter. But will people actually form groups that are so arbitrary? And could something as trivial as a randomly assigned name tag color serve as a fault line during group formation? In this study, we use in vivo behavioral tracking (IBT) to precisely and unobtrusively track samples of participants as they assort repeatedly into groups. We find that participants do form groups on the basis of their randomly assigned name tag colors, but that name tag homophily emerges over time, becoming stronger in subsequent groups. Our results suggest that people are unconsciously or consciously biased toward group similarity, even when similarities are essentially meaningless. Our study has implications for theories of intergroup relations and social identity. It also demonstrates the utility of applying real-time tracking to study group formation.

Giving to versus Taking from In- and Out-Group Members

In this experiment, we test whether subjects’ responses to variations in the action set in a dictator game depends on induced group identities. The action set includes choices in which the dictator can either give money to or take money from the other player. As an extension to the anonymous setting, we introduce induced group identities using the minimal group paradigm. Based on a dictator game conducted with more than 300 students in Indonesia, we implement a full factorial design in order to analyze the framing of the action set in a varied cultural context and to examine varied prevalence of social norms given a group identity context. If group identity is not salient, we find that participants are slightly more generous when they have an opportunity to give to rather than to take from the recipient. However, when participants are matched with in-group members, this result is reversed and highly significant. The result of differing responses to framing effects in within-group interactions compared to a neutral setting are largely ascribed to the varied compliance with existing social norms.