Daniel Fessler

University of California, Los Angeles | UCLA · Department of Anthropology

People vary both in their embrace of their society’s traditions, and in their perception of hazards as salient and necessitating a response. Over evolutionary time, traditions have offered avenues for addressing hazards, plausibly resulting in linkages between orientations toward tradition and orientations toward danger. Emerging research documents...

Witnessing altruistic behaviour can elicit moral elevation, an emotion that motivates prosocial cooperation. This emotion is evoked more strongly when the observer anticipates that other people will be reciprocally cooperative. Coalitionality should therefore moderate feelings of elevation, as whether the observer shares the coalitional affiliation...

Pain is a critical internal regulator of current and future behavior. However, pain also constitutes a tactical liability in agonistic interpersonal conflict. Therefore, information about the pain sensitivity of others should play a functional role in assessments of the formidability of prospective foes or allies. Compared to an individual known to...

When current conditions are probabilistically less suitable for successful reproduction than future conditions, females may prevent or delay reproduction until conditions improve. Throughout human evolution, social support was likely crucial to female reproductive success. Women may thus have evolved fertility regulation systems sensitive to cues f...

Jagiello et al.'s bifocal stance theory provides a useful theoretical framework for attempting to understand the connection between greater adherence to traditional norms and greater sensitivity to threats in the world. Here, we examine the implications of the instrumental and ritual stances with regard to various evolutionary explanations for trad...

The evolutionary fitness payoffs of moral condemnation are greatest within an individual’s immediate social milieu. Accordingly, insofar as human moral intuitions have been shaped by adaptive design, we can expect transgressive harms to be perceived as more wrong when transpiring in the here and now than when occurring at a distance, or with the ap...

There is considerable evidence that beliefs in supernatural punishment decrease self-interested behavior and increase cooperation amongst group members. To date, research has largely focused on beliefs concerning omniscient moralistic gods in large-scale societies. While there is an abundance of ethnographic accounts documenting fear of supernatura...

People vary in the extent to which they embrace their society’s traditions, impacting a range of social and political phenomena. People also vary in the degree to which they perceive disparate dangers as salient and necessitating a response. Over evolutionary time, traditions likely regularly offered direct and indirect avenues for addressing hazar...

Moral elevation, an emotion for prosocial cooperation elicited by witnessing altruistic behavior, is moderated by baseline expectations of other people’s cooperativeness. In line with the likely payoffs of cooperation to the observer, less elevation is evoked when others are expected to be less reciprocally cooperative. Coalitionality should theref...

Disgust has long been viewed as a primary motivator of defensive responses to threats posed by both microscopic pathogens and macroscopic ectoparasites. Although disgust can defend effectively against pathogens encountered through ingestion or incidental contact, it offers limited protection against ectoparasites, which actively pursue a host and a...

Disgust has long been viewed as a primary motivator of defensive responses to threats posed by both microscopic pathogens and macroscopic ectoparasites. Although disgust can defend effectively against pathogens encountered through ingestion or incidental contact, it offers limited protection against ectoparasites, which actively pursue a host and a...

Social liberals tend to be less pathogen-avoidant than social conservatives, a pattern consistent with a model wherein ideological differences stem from differences in threat reactivity. Here we investigate if and how individual responses to a shared threat reflect those patterns of ideological difference. In seeming contradiction to the general as...

When current conditions are probabilistically less suitable for successful reproduction than future conditions, females may prevent or delay reproduction until conditions improve. Throughout human evolution, social support was likely crucial to female reproductive success. Women may thus have evolved fertility regulation systems sensitive to cues f...

Background and objectives Life History Theory (LHT) describes trade-offs that organisms make with regard to three investment pathways: growth, maintenance, and reproduction. In light of the reparative functions of sleep, we examine sleep behaviors and corresponding attitudes as proximate manifestations of an individual’s underlying relative priorit...

Consistent with a threat-bias model of ideological differences, social liberals have been shown to be less pathogen-avoidant than tradition-valuing social conservatives. However, particularly when pathogen threat occurs at a societal level, additional factors may influence individual responses. In the current pandemic, the more socially conservativ...

Decades of research conducted in Western, Educated, Industrialized, Rich, & Democratic (WEIRD) societies have led many scholars to conclude that the use of mental states in moral judgment is a human cognitive universal, perhaps an adaptive strategy for selecting optimal social partners from a large pool of candidates. However, recent work from a mo...

While associated with extreme terrorist organizations in modern times, extensive accounts of grisly acts of violence exist in the archeological, historical, and ethnographic records. Though reasons for this dramatic form of violence are multifaceted and diverse, one possibility is that violence beyond what is required to win a conflict is a method...

A unique emotion, elevation, is thought to underlie prosocial contagion, a process whereby witnessing a prosocial act leads to acting prosocially. Individuals differ in their propensity to experience elevation, and thus their proneness to prosocial contagion, but little is known about the causes of such variation. We introduce an adaptationist mode...

Background. Despite the protection offered by bicycle helmets, their use varies substantially across populations, and is frequently lower among bikeshare cyclists than among other cyclists.Methods. We conducted an observational study of helmet use over eight months at five locations across two university campuses in Los Angeles, California, U.S.A.R...

While associated with extreme terrorist organizations in modern times, extensive accounts of grisly acts of violence exist in the archeological, historical, and ethnographic records. Though reasons for this dramatic form of violence are multifaceted and diverse, one possibility is that violence beyond what is required to win a conflict is a method...

A unique emotion, elevation, is thought to underlie prosocial contagion, a process whereby witnessing a prosocial act leads to acting prosocially. Individuals differ in their propensity to experience elevation, and thus their proneness to prosocial contagion, but little is known about the causes of such variation. We introduce an adaptationist acco...

Fitness is enhanced by determining when to behave prosocially. Elevation, an uplifting emotion elicited by witnessing exemplary prosociality, upregulates prosociality in the presence of prosocial others, as such contexts render prosociality profitable and/or antisociality costly. Prior research examines responses to a single highly prosocial indivi...

Conservatives and liberals have previously been shown to differ in the propensity to view socially-transmitted information about hazards as more plausible than that concerning benefits. Given differences between conservatives and liberals in threat sensitivity and dangerous-world beliefs, correlations between political orientation and negatively-bi...

Survey instruments for Study 2. (PDF)

Survey instruments for Study 1. (PDF)

Laughter is a nonverbal vocalization occurring in every known culture, ubiquitous across all forms of human social interaction. Here, we examined whether listeners around the world, irrespective of their own native language and culture, can distinguish between spontaneous laughter and volitional laughter—laugh types likely generated by different vo...

Purpose The perceived support of supernatural agents has been historically, ethnographically, and theoretically linked with confidence in engaging in violent intergroup conflict. However, there have been scant experimental investigations of such links to date, and the extant evidence derives largely from indirect laboratory methods of limited ecolo...

The emotion disgust motivates costly behavioral strategies that mitigate against potentially larger costs associated with pathogens, sexual behavior, and moral transgressions. Because disgust thereby regulates exposure to harm, it is by definition a mechanism for calibrating decision making under risk. Understanding this illuminates two features of...

Currently, disgust is regarded as the main adaptation for defence against pathogens and parasites in humans. Disgust's motivational and behavioural features, including withdrawal, nausea, appetite suppression and the urge to vomit, defend effectively against ingesting or touching sources of pathogens. However, ectoparasites do not attack their host...

Grief is characterized by a number of cardinal cognitive symptoms, including preoccupation with thoughts of the deceased and vigilance towards indications that the deceased is in the environment. Compared to emotional symptoms, little attention has been paid to the ultimate function of vigilance in grief. Drawing on signal-detection theory, we prop...

The target article argues that contempt is a sentiment, and that sentiments are the deep structure of social affect. The 26 commentaries meet these claims with a range of exciting extensions and applications, as well as critiques. Most significantly, we reply that construction and emergence are necessary for, not incompatible with, evolved design,...

Contempt is typically studied as a uniquely human moral emotion. However, this approach has yielded inconclusive results. We argue this is because the folk affect concept “contempt” has been inaccurately mapped onto basic affect systems. “Contempt” has features that are inconsistent with a basic emotion, especially its protracted duration and frequ...

Political conservatives have been widely documented to regard out-group members as hostile, perceive individuals of ambiguous intent as malevolent, and favor aggressive solutions to intergroup conflict. A growing literature indicates that potential violent adversaries are represented using the dimensions of envisioned physical size/strength to summ...

To benefit from information provided by others, people must be somewhat credulous. However, credulity entails risks. The optimal level of credulity depends on the relative costs of believing misinformation versus failing to attend to accurate information. When information concerns hazards, erroneous incredulity is often more costly than erroneous c...

Comparing mortuary rituals across 57 representative cultures extracted from the Human Relations Area Files, this paper demonstrates that kin of the deceased engage in behaviours to prepare the deceased for disposal that entail close and often prolonged contact with the contaminating corpse. At first glance, such practices are costly and lack obviou...

Among the Karo of Indonesia, the frequency of matrilateral cross-cousin (impal) marriage has declined in recent decades. We conducted a vignette experiment to assess the contributions of a handful of factors in shaping this pattern. Surprisingly, we found that cosocialization of a hypothetical woman with her impal led to increased judgments of marr...

One cognitive facet of the adaptive response to the absence of a valued relationship partner is increased vigilance towards indications of the agent's return, manifested in part as a lowered threshold for the detection of such indications. However, increased vigilance is dysfunctional when death is the cause of the partner's absence. Reliable cues...

The direct adaptive impact of rituals and other forms of behavior dictated or shaped by culture may be one factor influencing their persistence or lack thereof over time. Given that physical contact is a common means through which transmissible disease is spread, we explored the possibility that levels of normative physical contact would be negativ...

Laughter is a nonverbal vocal expression that often communicates positive affect and cooperative intent in humans. Temporally coincident laughter occurring within groups is a potentially rich cue of affiliation to overhearers. We examined listeners’ judgments of affiliation based on brief, decontextualized instances of colaughter between either est...

Polycystic ovary syndrome (PCOS) is a prehistoric complex genetic trait, perhaps dating back at least 50,000 years. The disorder also represents an evolutionary paradox, demonstrating clear reproductive disadvantages (i.e., lack of evolutionary fitness), albeit persisting tens of thousands of years. Here we examine possible explanations for this pa...

Synchronized behavior is a common feature of martial drills and military parades in many societies. Hagen and colleagues (Hagen & Bryant, 2003; Hagen & Hammerstein, 2009) hypothesized that the intentional enactment of synchronized behavior evolved as a means of signaling coalitional strength, as individuals who can synchronize are able to act in co...

Laughter is a nonverbal vocal expression that often communicates positive affect and cooperative intent in humans. Temporally coincident laughter occurringwithin groups is a potentially rich cue of affiliation to overhearers. We examined listeners’ judgments of affiliation based on brief, decontextualized instances of colaughter between either esta...

Significance It is widely considered a universal feature of human moral psychology that reasons for actions are taken into account in most moral judgments. However, most evidence for this moral intent hypothesis comes from large-scale industrialized societies. We used a standardized methodology to test the moral intent hypothesis across eight tradi...

Fever, the rise in body temperature set point in response to infection or injury, is a highly conserved trait among vertebrates, and documented in many arthropods. Fever is known to reduce illness duration and mortality. These observations present an evolutionary puzzle: why has fever continued to be an effective response to fast-evolving pathogeni...

Our paper [1] compared two competing hypotheses. The hypothesis that we label universalistic moral evaluation holds that a definitional feature of reasoning about moral rules is that, ceteris paribus, judgements of violations of rules concerning harm, rights or justice will be insensitive to spatial or temporal distance or the opinions of authority...

The imagined support of benevolent supernatural agents attenuates anxiety and risk perception. Here, we extend these findings to judgments of the threat posed by a potentially violent adversary. Conceptual representations of bodily size and strength summarize factors that determine the relative threat posed by foes. The proximity of allies moderate...

This chapter offers a selective survey of the contributions that evolutionary anthropology (EA) can make to research in evolutionary psychology (EP). Drawing on paleoanthropology, we underscore the importance of phylogeny in understanding adaptations, including the kludgy nature of many, and the conflicts that arise among them. This approach unders...

People cleave to ideological convictions with greater intensity in the aftermath of threat. The posterior medial frontal cortex (pMFC) plays a key role in both detecting discrepancies between desired and current conditions and adjusting subsequent behavior to resolve such conflicts. Building on prior literature examining the role of the pMFC in shi...

We hypothesize that, paralleling the evolution of human hierarchies from social structures based on dominance to those based on prestige, adaptations for representing status are derived from those for representing relative fighting capacity. Because both violence and status are important adaptive challenges, the mind contains the ancestral represen...

Chapter accepted for publication in The Handbook of Evolutionary Psychology, D. M. Buss, ed.

Displaying markers of coalitional affiliation is a common feature of contemporary life. In situations in which interaction with members of rival coalitions is likely, signaling coalitional affiliation may simultaneously constitute an implicit challenge to opponents and an objective commitment device, binding signalers to their coalitions. Individua...

Human moral judgement may have evolved to maximize the individual's welfare given parochial culturally constructed moral systems. If so, then moral condemnation should be more severe when transgressions are recent and local, and should be sensitive to the pronouncements of authority figures (who are often arbiters of moral norms), as the fitness pa...

Successful use of fire has been essential to survival throughout the majority of human history-an environmental pressure that may have led to cognitive mechanisms dedicated to attaining mastery of fire manipulation and control. Concordant with this hypothesis is the fact that, despite its inherent danger, the frivolous use of fire remains firmly em...

Sexual arousal is a motivational state that moves humans toward situations that inherently pose a risk of disease transmission. Disgust is an emotion that adaptively moves humans away from such situations. Incongruent is the fact that sexual activity is elementary to human fitness yet involves strong disgust elicitors. Using an experimental paradig...

Comparing mortuary rituals across 57 representative cultures extracted from the Human Relations Area Files, this paper demonstrates that kin of the deceased engage in behaviors to prepare the deceased for disposal that entail close and often prolonged contact with the contaminating corpse. At first glance, such practices are costly and lack obvious...

Narcotics Anonymous (NA) supports long-term recovery for those addicted to drugs. Paralleling social dynamics in many small-scale societies, NA exhibits tension between egalitarianism and prestige-based hierarchy, a problem exacerbated by the addict's personality as characterized by NA's ethnopsychology. We explore how NA's central principle of ano...

The determinants of conversational dominance are not well understood. We used videotaped triadic interactions among unacquainted same-sex American college students to test predictions drawn from the theoretical distinction between dominance and prestige as modes of human status competition. Specifically, we investigated the effects of physical form...

The frequency of homoerotic behavior among individuals who do not identify as having an exclusively homosexual sexual orientation suggests that such behavior potentially has adaptive value. Here, we define homoerotic behavior as intimate erotic contact between members of the same sex and affiliation as the motivation to make and maintain social bon...

Men are more prone than women to both commit physical violence and engage in nonviolent activities entailing the risk of injury or death. The Crazy Bastard Hypothesis (FESSLER et al. 2014a) addresses this conjunction, arguing that nonviolent physical risk-taking communicates information about the actor's agonistic formidability, as individuals who...

We believe that the concept of the behavioral immune system (BIS) picks out an important set of phenomena, namely, the relationships between the immune system and disease-avoidant psychology. However, our enthusiasm is tempered by the recognition that (a) there are unresolved ambiguities in the BIS concept, which has been used in a variety of (some...

Purpose: Across taxa, strength and size are elementary determinants of relative fighting capacity; in species with complex behavioral repertoires, numerous additional factors also contribute. When many factors must be considered simultaneously, decision-making in agonistic contexts can be facilitated through the use of a summary representation. Siz...

In ‘The nature of moral judgments and the extent of the moral domain’, Fraser (20121. Fraser, B. 2012. “The nature of moral judgements and the extent of the moral domain.” Philosophical Explorations 15 (1): 1–16. doi:10.1080/13869795.2012.647356.[Taylor & Francis Online], [Web of Science ®]View all references) criticises findings by Kelly et al. (2...

Paralleling behaviours in other species, synchronized movement is central to institutionalized collective human activities thought to enhance cooperation, and experiments demonstrate that synchrony has this effect. The influence of synchrony on cooperation may derive from an evolutionary history wherein such actions served to signal coalitional str...

Emotion perception is necessarily imprecise, leading to possible overperception or underperception of a given emotion extant in a target individual. When the costs of these two types of errors are recurrently asymmetrical, categorization mechanisms can be expected to be biased to commit the less costly error. Contextual factors can influence this a...

The functions of cultural beliefs are often opaque to those who hold them. Accordingly, to benefit from cultural evolution's ability to solve complex adaptive problems, learners must be credulous. However, credulity entails costs, including susceptibility to exploitation, and effort wasted due to false beliefs. One determinant of the optimal level...

Due to altriciality and the importance of embodied capital, children’s fitness is contingent on parental investment. Injury suffered by a parent therefore degrades the parent’s fitness both by constraining reproduction and by diminishing the fitness of existing offspring. Due to the latter added cost, compared to non-parents, parents should be more...