Daniel Conroy-Beam and David M. Buss
The importance of groups is underscored by the need for two sections on the psychology of group living. Chapters in this section focus on adaptations that emerge as features of our species' groupish nature. Living in groups offers our species a bounty of benefits and costs, but also exposes us to a raft of new problems. These include coordinating belief and action, accumulating and transmitting knowledge, and knowing and exploiting oneself, other people, and group strengths. From these problems emerge morality, reputation, prejudice, and perhaps culture itself—topics that compose a cutting edge of evolutionary psychology. The chapters in this section represent large advances into previously little-touched psychological territory and are likely to become pillars within the broader foundation of evolutionary psychology.
No treatment of evolutionary psychology would be complete without a detailed examination of cultural evolution—the processes by which cultural variants are invented, selectively jettisoned, and selectively retained, resulting in cumulative change over time in ideas, inventions, values, beliefs, artifacts, and institutions. Maciej Chudek, Michael Muthukrishna, and Joe Henrich take up this daunting challenge with a superb chapter on the processes by which cultural evolution takes place (Chapter 30). They argue that cultures do indeed evolve in ways that do not rely on genes and strict replicators. The evolution of the huge human capacity for social learning, and hence cultural learning, they argue, enabled our species to cross a critical threshold to become a truly cultural species. They articulate some of the evolved psychological adaptations on which cultural evolution relies, such as conformist transmission and credibility enhancing displays. They end with a discussion of gene-culture coevolution. This critical chapter provides a conceptual roadmap for the future of the uniquely human components of “the cultural animal” that is us.
Humans have also been called “the moral animal,” and for good reason. Rob Kurzban and Peter DeScioli provide an outstanding original chapter on morality (Chapter 31). It focuses on moral judgment—how people judge the actions of others to be right or wrong. The complex cognitive psychology of moral judgment is inexorably linked with moral emotions, particularly moralistic anger and moralistic disgust. These emotions, in turn, often motivate punishment of those deemed to have morally transgressed. Importantly, Kurzban and DeScioli hypothesize that moral judgments serve a critical and underappreciated adaptive function—to guide coalitional side-taking in times of social conflict. The moral side-taking hypothesis generates a raft of novel predictions, and is likely to produce a sea change in thinking about morality in the next decade.
If morality provides one solution to the problem of within-group alliance and coordination, adaptations for hierarchy provide another. Mark van Vugt and Joshua Tybur (Chapter 32) provide an excellent chapter on status hierarchies, arguing that their complexity can be understood only by deep knowledge of the multiple psychological adaptations involved. They use evolutionary game theory as one tool to explore these adaptations, and then turn to the links between status and hormones, physique, verbal and nonverbal indicators, and emotions such as anxiety, shame, rage, and depression. They then explore sex differences in status striving and other elements of male and female psychology of status. They end with the evolutionary psychology of leadership, offering the “service for prestige” hypothesis to explain the mutual adaptive benefits afforded to both leaders and those who are led. Since status hierarchies are universal and reproductively relevant resources are inextricably linked with position within status hierarchies, this chapter opens up new and largely unexplored territory for discoveries in this domain.
One such domain is that of reputation, explored in depth by Pat Barclay (Chapter 33). Although humans are not the only species in which individuals hold reputations, our unique capacity for language renders reputation exceptionally important. As with status hierarchies, humans are likely to possess multiple adaptations for dealing with reputation. These include cultivating one's own reputation, influencing or manipulating the reputations of others in what has sometimes been called “information warfare,” and even skepticism about the value of the information depending on its source. Although “gossip” is sometimes seen as a trivial and idle way of spending time, Barclay argues that it is a critical form of manipulating reputations. Humans develop reputations as cooperators (ability and willingness to confer benefits) as well as aggressors (cost-inflicting proclivities). Barclay's chapter also opens up new territory by posting key adaptationist landmarks for future intrepid researchers who explore the critically important, but largely overlooked, domain of social reputation.
Cristine Legare and Rachel Watson-Jones follow with a terrific chapter on ritual (Chapter 34)—one unique way in which humans across cultures solve the coordination problem. They argue that rituals serve vital functions—identifying group members, ensuring commitment to the group, facilitating cooperation within the group, increasing cohesion within the group, and critically, coordinating group or coalitional action. They draw on a unique combination of empirical studies from samples of children and adults, offering a developmental as well as an evolutionary perspective on the origins of ritual. Along the way, they provide key insights ranging from ethnographic anthropological studies to experimental studies of the effects of ostracism on ritual, overimitation, and conformity in children. This chapter paves the way for future psychologists in a discipline that has overlooked the importance of ritual.
Ara Norenzayan (Chapter 35) provides an insightful evolutionary psychological analysis of the evolution of religion. He argues that religion, a culturally universal phenomenon in varying forms, is best understood as a synthetic combination of by-products of a suite of cognitive adaptations along with adaptations themselves, such as costly signaling in the service of cooperation. Religions themselves have evolved, he argues, not through standard Darwinian selection, but rather through cultural evolution as a partial solution to the problem of large-scale cooperation among hundreds, thousands, or millions of individuals. Norenzayan's theory of religion, particularly the emergence of “Big Gods” as a cultural solution to the problem of large-scale cooperation, has the signal virtue of synthesizing adaptationist, by-product, and cultural evolutionary perspectives.
Steven Pinker ends the section on a strong note with his incisive contribution to the ongoing debate surrounding group selection (Chapter 36). The title of his essay—The False Allure of Group Selection—provides more than a hint about his skepticism of group selection as an explanatory scheme. He starts by enumerating the many different senses in which scholars currently use “group selection,” including as a distinct form of selection, any behavior that involves groups, and a redescription of genic selection using a different accounting system that defines practically any social interaction, however fleeting, as a “group.” He argues cogently that these many uses of “group selection” create large-scale confusion in which anything that loosely involves groups or group living is attributed to the causal process of “group selection.” Some theorists are on record as disagreeing with Pinker's arguments, but his proposed solution must be taken seriously: “I offer a simple solution: Stop using the term group selection as a loose synonym for the evolution of group living, group competition, group norms, group practices, social networks, culture, selflessness, kindness, empathy, altruism, morality, clannishness, tribalism, or coalitional aggression.” Pinker's essay should be required reading for everyone in the evolutionary sciences.