What Makes Us Smart?

How did humans become clever enough to live in nearly every major ecosystem on earth, create vaccines against deadly plagues, explore the oceans depths, and routinely traverse the globe at 30,000 feet in aluminum tubes while nibbling on roasted almonds? Drawing on recent developments in our understanding of human evolution, we consider what makes us distinctively smarter than other animals. Contrary to conventional wisdom, human brilliance emerges not from our innate brainpower or raw computational capacities, but from the sharing of information in communities and networks over generations. We review how larger, more diverse, and more optimally interconnected networks of minds give rise to faster innovation and how the cognitive products of this cumulative cultural evolutionary process feedback to make us individually "smarter"-in the sense of being better at meeting the challenges and problems posed by our societies and socioecologies. Here, we consider not only how cultural evolution supplies us with "thinking tools" (like counting systems and fractions) but also how it has shaped our ontologies (e.g., do germs and witches exist?) and epistemologies, including our notions of what constitutes a "good reason" or "good evidence" (e.g., are dreams a source of evidence?). Building on this, we consider how cultural evolution has organized and distributed cultural knowledge and cognitive tasks among subpopulations, effectively shifting both thinking and production to the level of the community, population, or network, resulting in collective information processing and group decisions. Cultural evolution can turn mindless mobs into wise crowds by facilitating and constraining cognition through a wide variety of epistemic institutions-political, legal, and scientific. These institutions process information and aid better decision-making by suppressing or encouraging the use of different cultural epistemologies and ontologies.

The Agential View of Misfortune

In many traditional, small-scale societies, death and other misfortunes are commonly explained as a result of others' malign occult agency. Here, we call this family of epistemic tendencies "the agential view of misfortune." After reviewing several ethnographic case studies that illustrate this view, we argue that its origins and stability are puzzling from an evolutionary perspective. Not only is the agential view of misfortune false; it imposes costs on individuals and social groups that seem to far outweigh whatever benefits the view might provide. We thus doubt that the agential view of misfortune is explainable in terms of adaptive effects. However, neither does it seem readily explainable as a consequence of belief formation strategies that are on the whole adaptive (as is plausibly the case for certain other of our false beliefs, including some that are costly). Accordingly, we contend that the commonness of the agential view of misfortune demands a special evolutionary explanation of some kind. We provide a partial explanation of this phenomenon by highlighting the adaptive benefits that often flow to occult specialists in environments where the agential view of misfortune is entrenched. What this does not explain, however, is the general lack of resistance we observe in response to occultists' exploitative behaviours over (cultural) evolutionary timescales. We conclude by canvassing a few possible explanations for this puzzling lack of resistance, and while we commit ourselves to none, we do find one option more promising than the others.

Curious about threats: Morbid curiosity and interest in conspiracy theories in US adults

Conspiracy theories allege secret plots between two or more powerful actors to achieve an outcome, sometimes explaining important events or proposing alternative understandings of reality in opposition to mainstream accounts, and commonly highlight the threat presented by the plot and its conspirators. Research in psychology proposes that belief in conspiracy theories is motivated by a desire to understand threats and is predicted by increased anxiety. Morbid curiosity describes the tendency to seek out information about threatening or dangerous situations and is associated with an interest in threat-related entertainment and increased anxiety. Across three studies, we investigated the relationship between morbid curiosity and conspiracy theories in US-based samples. We found that higher trait morbid curiosity was associated with higher general conspiracist beliefs (Study 1) and the perceived threat of conspiratorial explanations of events (Study 2). Using a behavioural choice paradigm, we found that participants who chose to investigate morbidly curious stimuli were more likely to choose to learn about conspiratorial explanations for events (Study 3). Greater curiosity about the minds of dangerous people was consistently the strongest predictor of conspiratorial ideation and interest. These results suggest that morbid curiosity is an important but hitherto unstudied predictor of conspiratorial interest and belief.

The puritanical moral contract: Purity, cooperation, and the architecture of the moral mind

Commentators raise fundamental questions about the notion of purity (sect. R1), the architecture of moral cognition (sect. R2), the functional relationship between morality and cooperation (sect. R3), the role of folk-theories of self-control in moral judgment (sect. R4), and the cultural variation of morality (sect. R5). In our response, we address all these issues by clarifying our theory of puritanism, responding to counter-arguments, and incorporating welcome corrections and extensions.

Universality, domain-specificity, and development of psychological responses to music

Humans can find music happy, sad, fearful, or spiritual. They can be soothed by it or urged to dance. Whether these psychological responses reflect cognitive adaptations that evolved expressly for responding to music is an ongoing topic of study. In this Review, we examine three features of music-related psychological responses that help to elucidate whether the underlying cognitive systems are specialized adaptations: universality, domain-specificity, and early expression. Focusing on emotional and behavioural responses, we find evidence that the relevant psychological mechanisms are universal and arise early in development. However, the existing evidence cannot establish that these mechanisms are domain-specific. To the contrary, many findings suggest that universal psychological responses to music reflect more general properties of emotion, auditory perception, and other human cognitive capacities that evolved for non-musical purposes. Cultural evolution, driven by the tinkering of musical performers, evidently crafts music to compellingly appeal to shared psychological mechanisms, resulting in both universal patterns (such as form-function associations) and culturally idiosyncratic styles.

Supernatural explanations across 114 societies are more common for natural than social phenomena

Humans across the globe use supernatural beliefs to explain the world around them. This article explores whether cultural groups invoke the supernatural more to explain natural phenomena (for example, storms, disease outbreaks) or social phenomena (for example, murder, warfare). Quantitative analysis of ethnographic text across 114 geographically and culturally diverse societies found that supernatural explanations are more prevalent for natural than for social phenomena, consistent with theories that ground the origin of religious belief in a human tendency to perceive intent and agency in the natural world. Despite the dominance of supernatural explanations of natural phenomena, supernatural explanations of social phenomena were especially prevalent in urbanized societies with more socially complex and anonymous groups. Our results show how people use supernatural beliefs as explanatory tools in non-industrial societies, and how these applications vary across small-scale communities versus large and urbanized groups.

Belief changes associated with psychedelic use

BACKGROUND

Psychedelic use is anecdotally associated with belief changes, although few studies have tested these claims.

AIM

Characterize a broad range of psychedelic occasioned belief changes.

SURVEY

A survey was conducted in 2374 respondents who endorsed having had a belief changing psychedelic experience. Participants rated their agreement with belief statements Before and After the psychedelic experience as well as at the time of survey administration.

RESULTS

Factor analysis of 45 belief statements revealed five factors: "Dualism," "Paranormal/Spirituality," "Non-mammal consciousness," "Mammal consciousness," and "Superstition." Medium to large effect sizes from Before to After the experience were observed for increases in beliefs in "Dualism" (β = 0.72), "Paranormal/Spirituality" (β = 0.90), "Non-mammal consciousness" (β = 0.72), and "Mammal consciousness" (β = 0.74). In contrast, negligible changes were observed for "Superstition" (β = -0.18).). At the individual item level, increases in non-physicalist beliefs included belief in reincarnation, communication with the dead, existence of consciousness after death, telepathy, and consciousness of inanimate natural objects (e.g., rocks). The percentage of participants who identified as a "Believer (e.g., in Ultimate Reality, Higher Power, and/or God, etc.)" increased from 29% Before to 59% After." At both the factor and individual item level, higher ratings of mystical experience were associated with greater changes in beliefs. Belief changes assessed after the experience (an average 8.4 years) remained largely unchanged at the time of survey.

CONCLUSIONS

A single psychedelic experience increased a range of non-physicalist beliefs as well as beliefs about consciousness, meaning, and purpose. Further, the magnitude of belief change is associated with qualitative features of the experience.

Subjective selection and the evolution of complex culture

Why is culture the way it is? Here I argue that a major force shaping culture is subjective (cultural) selection, or the selective retention of cultural variants that people subjectively perceive as satisfying their goals. I show that people evaluate behaviors and beliefs according to how useful they are, especially for achieving goals. As they adopt and pass on those variants that seem best, they iteratively craft culture into increasingly effective-seeming forms. I argue that this process drives the development of many cumulatively complex cultural products, including effective technology, magic and ritual, aesthetic traditions, and institutions. I show that it can explain cultural dependencies, such as how certain beliefs create corresponding new practices, and I outline how it interacts with other cultural evolutionary processes. Cultural practices everywhere, from spears to shamanism, develop because people subjectively evaluate them to be effective means of satisfying regular goals.

Moral disciplining: The cognitive and evolutionary foundations of puritanical morality

Why do many societies moralize apparently harmless pleasures, such as lust, gluttony, alcohol, drugs, and even music and dance? Why do they erect temperance, asceticism, sobriety, modesty, and piety as cardinal moral virtues? According to existing theories, this puritanical morality cannot be reduced to concerns for harm and fairness: It must emerge from cognitive systems that did not evolve for cooperation (e.g., disgust-based "purity" concerns). Here, we argue that, despite appearances, puritanical morality is no exception to the cooperative function of moral cognition. It emerges in response to a key feature of cooperation, namely that cooperation is (ultimately) a long-term strategy, requiring (proximately) the self-control of appetites for immediate gratification. Puritanical moralizations condemn behaviors which, although inherently harmless, are perceived as indirectly facilitating uncooperative behaviors, by impairing the self-control required to refrain from cheating. Drinking, drugs, immodest clothing, and unruly music and dance are condemned as stimulating short-term impulses, thus facilitating uncooperative behaviors (e.g., violence, adultery, free-riding). Overindulgence in harmless bodily pleasures (e.g., masturbation, gluttony) is perceived as making people slave to their urges, thus altering abilities to resist future antisocial temptations. Daily self-discipline, ascetic temperance, and pious ritual observance are perceived as cultivating the self-control required to honor prosocial obligations. We review psychological, historical, and ethnographic evidence supporting this account. We use this theory to explain the fall of puritanism in western, educated, industrialized, rich, and democratic (WEIRD) societies, and discuss the cultural evolution of puritanical norms. Explaining puritanical norms does not require adding mechanisms unrelated to cooperation in our models of the moral mind.

Same-sex competition and sexual conflict expressed through witchcraft accusations

There is significant cross-cultural variation in the sex of individuals most likely to be accused of practising witchcraft. Allegations of witchcraft might be a mechanism for nullifying competitors so resources they would have used become available to others. In this case, who is targeted may result from patterns of competition and conflict (same-sex or male-female) within specific relationships, which are determined by broader socio-ecological factors. Here we examine patterns of sex-specific accusations in historic cases from sub-Saharan Africa (N = 423 accusations). Male 'witches' formed the greater part of our sample, and were mostly accused by male blood-relatives and nonrelatives, often in connection to disputes over wealth and status. Accusations of women were mainly from kin by marriage, and particularly from husbands and co-wives. The most common outcomes were that the accused was forced to move, or suffered reputational damage. Our results suggest that competition underlies accusations and relationship patterns may determine who is liable to be accused.

When instrumental inference hides behind seemingly arbitrary conventions

We review recent evidence that game rules, rules of etiquette, and supernatural beliefs, that the authors see as “ritualistic” conventions, are in fact shaped by instrumental inference. In line with such examples, we contend that cultural practices that may appear, from the outside, to be devoid of instrumental utility, could in fact be selectively acquired and preserved because of their perceived utility.

Supernatural punishment beliefs as cognitively compelling tools of social control

Why do humans develop beliefs in supernatural entities that punish uncooperative behaviors? Leading hypotheses maintain that these beliefs are widespread because they facilitate cooperation, allowing their groups to outcompete others in intergroup competition. Focusing on within-group interactions, we present a model in which people strategically endorse supernatural punishment beliefs as intuitive tools of social control to manipulate others into cooperating. Others accept these beliefs, meanwhile, because they are made compelling by various cognitive biases: they appear to provide information about why misfortune occurs; they appeal to intuitions about immanent justice; they contain threatening information; and they allow believers to signal their trustworthiness. Explaining supernatural beliefs requires considering both motivations to invest in their endorsement and the reasons others adopt them.

Beyond social learning

Cultural evolution requires the social transmission of information. For this reason, scholars have emphasized social learning when explaining how and why culture evolves. Yet cultural evolution results from many mechanisms operating in concert. Here, we argue that the emphasis on social learning has distracted scholars from appreciating both the full range of mechanisms contributing to cultural evolution and how interactions among those mechanisms and other factors affect the output of cultural evolution. We examine understudied mechanisms and other factors and call for a more inclusive programme of investigation that probes multiple levels of the organization, spanning the neural, cognitive-behavioural and populational levels. To guide our discussion, we focus on factors involved in three core topics of cultural evolution: the emergence of culture, the emergence of cumulative cultural evolution and the design of cultural traits. Studying mechanisms across levels can add explanatory power while revealing gaps and misconceptions in our knowledge. This article is part of the theme issue 'Foundations of cultural evolution'.