Our discussion of the commentaries begins, at the evolutionary level, with issues raised by our account of the evolution of morality in terms of partner-choice mutualism. We then turn to the cognitive level and the characterization and workings of fairness. In a final section, we discuss the degree to which our fairness-based approach to morality extends to norms that are commonly considered moral even though they are distinct from fairness.

Group dynamics play an important role in the social interactions of both children and adults. A large amount of research has shown that merely being allocated to arbitrarily defined groups can evoke disproportionately positive attitudes toward one’s in-group and negative attitudes toward out-groups, and that these biases emerge in early childhood. This prompts important empirical questions with far-reaching theoretical and applied significance. How robust are these inter-group biases? Can biases be mitigated by behaviors known to bond individuals and groups together? (...) How can bonds be forged across existing group divides? To explore these questions, we examined the bonding effects of interpersonal synchrony on minimally constructed groups in a controlled experiment. In-group and out-group bonding were assessed using questionnaires administered before and after a task in which groups performed movements either synchronously or non-synchronously in a between-participants design. We also developed an implicit behavioral measure, the Island Game, in which physical proximity was used as an indirect measure of interpersonal closeness. Self-report and behavioral measures showed increased bonding between groups after synchronous movement. Bonding with the out-group was significantly higher in the condition in which movements were performed synchronously than when movements were performed non-synchronously between groups. The findings are discussed in terms of their importance for the developmental social psychology of group dynamics as well as their implications for applied intervention programs. (shrink)

Group ownership is ubiquitous—property is owned by countries, corporations, families, and clubs. However, people cannot understand group ownership by simply relying on their conceptions of ownership by individuals, as group ownership is subject to complexities that do not arise when property is individually owned. We report 6 experiments investigating whether children ages 3 to 6 understand group ownership. In Experiments 1 and 2 children were asked who different objects belong to, and they appropriately judged that certain objects are more likely (...) to belong to a group than to individual people. Experiments 3 and 4 investigated whether children understand the limits of group ownership. Children saw vignettes where agents modified or depleted property. Children ages 3 and older understood that individual members of a group should not deplete group-owned property, and children ages 5 and 6 understood that individual members should not modify group-owned property. Finally, Experiments 5 and 6 investigated whether children understand the benefits of group ownership. Children ages 5 and 6 judged that it is more acceptable for a group member to take group property than for a nonmember to do this, and children ages 4 to 6 judged that group members can take more group resources than can nonmembers. Together, these results are informative about how children conceive of group ownership rights, and about children’s conceptions of groups. 2017 APA, all rights reserved). (shrink)

Humans are an exceptionally cooperative species, but there is substantial variation in the extent of cooperation across societies. Understanding the sources of this variability may provide insights about the forces that sustain cooperation. We examined the ontogeny of prosocial behavior by studying 326 children 3–14 y of age and 120 adults from six societies (age distributions varied across societies). These six societies span a wide range of extant human variation in culture, geography, and subsistence strategies, including foragers, herders, horticulturalists, and (...) urban dwellers across the Americas, Oceania, and Africa. When delivering benefits to others was personally costly, rates of prosocial behavior dropped across all six societies as children approached middle childhood and then rates of prosociality diverged as children tracked toward the behavior of adults in their own societies. When prosocial acts did not require personal sacrifice, prosocial responses increased steadily as children matured with little variation in behavior across societies. Our results are consistent with theories emphasizing the importance of acquired cultural norms in shaping costly forms of cooperation and creating cross-cultural diversity. (shrink)