Recent studies reveal that violence significantly contributes to explaining individual’s facial preferences. Women who feel at higher risk of violence prefer less-masculine male faces. Given the importance of violence, we explore its influence on people’s preferences for a different physical trait. Masculinity correlates positively with male strength and weight or body mass index. In fact, masculinity and BMI tend to load on the same component of trait perception. Therefore we predicted that individuals’ perceptions of danger from violence will relate to (...) preferences for facial cues to low-BMI. In two studies in Colombia, men and women from Bogota, Medellin, and surrounding communities were shown pairs of faces transformed to epitomize the shape correlates of men with high or low-BMI. The images were of European, Salvadoran, or Colombian men. Participants were asked to choose the face they considered most attractive. Subsequently, participants answered a survey about their health, media access, education level, and experiences/perceptions of violence in study 1 and about specific types of violence in study 2. Results from both studies showed that women who experienced/perceived higher levels of violence preferred faces of low-BMI Salvadoran men. Preferences for low-BMI facial cues were significantly explained by violence, even after controlling for all other variables. These results may reflect women’s strategy to avoid male partners capable of inflicting harm. (shrink)

Archer presents a traditional view of intrasexual competition. Knowledge of a species' social structure provides a more complete picture. Human males compete against individuals with whom they may cooperate later in inter-group aggression. By contrast, females compete against individuals for a mate's continued support. Females' aggression may aim at eliminating the competition, whereas males simply may attempt to dominate others.

In this commentary, I review diverse lines of research conducted at both the macrosocial and microbehavioral level that dispute the view that cruelty is inherently gratifying. Expressions of pain and suffering typically inhibit rather than reinforce cruel conduct in humans. With regard to functional value, cruelty has diverse personal and social effects, not just the alluring benefits attributed to it.

I argue that the magnitude and nature of sex differences in aggression, their development, causation, and variability, can be better explained by sexual selection than by the alternative biosocial version of social role theory. Thus, sex differences in physical aggression increase with the degree of risk, occur early in life, peak in young adulthood, and are likely to be mediated by greater male impulsiveness, and greater female fear of physical danger. Male variability in physical aggression is consistent with an alternative (...) life history perspective, and context-dependent variability with responses to reproductive competition, although some variability follows the internal and external influences of social roles. Other sex differences, in variance in reproductive output, threat displays, size and strength, maturation rates, and mortality and conception rates, all indicate that male aggression is part of a sexually selected adaptive complex. Physical aggression between partners can be explained using different evolutionary principles, arising from the conflicts of interest between males and females entering a reproductive alliance, combined with variability following differences in societal gender roles. In this case, social roles are particularly important since they enable both the relatively equality in physical aggression between partners from Western nations, and the considerable cross-national variability, to be explained. (shrink)

Cruelty is the deliberate infliction of physical or psychological pain on other living creatures, sometimes indifferently, but often with delight. Though cruelty is an overwhelming presence in the world, there is no neurobiological or psychological explanation for its ubiquity and reward value. This target article attempts to provide such explanations by describing three stages in the development of cruelty. Stage 1 is the development of the predatory adaptation from the Palaeozoic to the ethology of predation in canids, felids, and primates. (...) Stage 2, through palaeontological and anthropological evidence, traces the emergence of the hunting adaptation in the Pliocene, its development in early hominids, and its emotional loading in surviving forager societies. This adaptation provides an explanation for the powerful emotions – high arousal and strong affect – evoked by the pain-blood-death complex. Stage 3 is the emergence of cruelty about 1.5 million years ago as a hominid behavioural repertoire that promoted fitness through the maintenance of personal and social power. The resulting cultural elaborations of cruelty in war, in sacrificial rites, and as entertainment are examined to show the historical and cross-cultural stability of the uses of cruelty for punishment, amusement, and social control. Effective violence prevention must begin with perpetrators, not victims. If the upstream approaches to violence prevention advocated by the public-health model are to be effective, psychologists must be able to provide violence prevention workers with a fine-grained understanding of perpetrator gratifications. This is a distasteful task that will compel researchers to interact with torturers and abusers, and to acknowledge that their gratifications are rooted in a common human past. It is nonetheless an essential step in developing effective strategies for the primary prevention of violence. Key Words: compassion; cruelty; entertainment industry; evolutionary psychology; intraspecific killing; pain; predation; punishment; torture; violence prevention. Correspondence:c1 Correspondence to: West Hill House, 6 Swains Lane, Highgate, London N6 6QS, United Kingdom. (shrink)

The pioneering ideas of Glenn D. Paige for a paradigm shift from killing to nonkilling are highlighted. The relevance of anthropology for this paradigm is advanced. The accumulating scientific evidence proves that nonviolent and peaceful societies not only exist, but are actually the norm throughout human prehistory and history. This scientific fact is elucidated through a historical inventory of the most important documentation. Ethnographic cases are summarized of the Semai as a nonviolent society, the transition from killing to nonkilling of (...) the Waorani, and the critiques of the representation of the Yanomami as a killing society. Several of the most important cross-cultural studies are discussed. The assertions of some of the most vocal opponents to this paradigm are refuted. The systemic cultural and ideological bias privileging violence and war over nonviolence and peace is documented. (shrink)

I summarise certain aspects of Paul Feyerabend’s account of the development of Western rationalism, show the ways in which that account is supposed to run up against an alternative, that of Karl Popper, and then try to give a preliminary comparison of the two. My interest is primarily in whether what Feyerabend called his ‘story’ constitutes a possible history of our epistemic concepts and their trajectory. I express some grave reservations about that story, and about Feyerabend’s framework, finding Popper’s views (...) less problematic here. However, I also suggest that one important aspect of Feyerabend’s material, his treatment of religious belief, can be given an interpretation which makes it tenable, and perhaps preferable to a Popperian approach. (shrink)

Evolutionary psychologists have suggested that confidence and conservatism promoted aggression in our ancestral past, and that this may have been an adaptive strategy given the prevailing costs and benefits of conflict. However, in modern environments, where the costs and benefits of conflict can be very different owing to the involvement of mass armies, sophisticated technology, and remote leadership, evolved tendencies toward high levels of confidence and conservatism may continue to be a contributory cause of aggression despite leading to greater costs (...) and fewer benefits. The purpose of this paper is to test whether confidence and conservatism are indeed associated with greater levels of aggression—in an explicitly political domain. We present the results of an experiment examining people’s levels of aggression in response to hypothetical international crises (a hostage crisis, a counter-insurgency campaign, and a coup). Levels of aggression (which range from concession to negotiation to military attack) were significantly predicted by subjects’ (1) confidence that their chosen policy would succeed, (2) score on a liberal-conservative scale, (3) political party affiliation, and (4) preference for the use of military force in real-world U.S. policy toward Iraq and Iran. We discuss the possible adaptive and maladaptive implications of confidence and conservatism for the prospects of war and peace in the modern world. (shrink)

Human aggression has two important dimensions: within-group aggression and between-group aggression. Archer offers an excellent treatment of the former only. A full explanation of sex differences in aggression will fail without accounting for our history of inter-group aggression, which has deep evolutionary roots and specific psychological adaptations. The causes and consequences of inter-group aggression are dramatically different for males and females.

In the absence of explicit punitive sanctions, why do individuals voluntarily participate in intergroup warfare when doing so incurs a mortality risk? Here we consider the motivation of individuals for participating in warfare. We hypothesize that in addition to other considerations, individuals are incentivized by the possibility of rewards. We test a prediction of this “cultural rewards war-risk hypothesis” with ethnographic literature on warfare in small-scale societies. We find that a greater number of benefits from warfare is associated with a (...) higher rate of death from conflict. This provides preliminary support for the relationship between rewards and participation in warfare. (shrink)

Coalitions and alliances are core aspects of human behavior. All societies recognize alliances among communities, usually based in part on kinship and marriage. Aggression between groups is ubiquitous, often deadly, fueled by revenge, and can have devastating effects on general human welfare. Given its significance, it is surprising how little we know about the neurobiological and hormonal mechanisms that underpin human coalitionary behavior. Here we first briefly review a model of human coalitionary behavior based on a process of runaway social (...) selection. We then present several exploratory analyses of neuroendocrine responses to coalitionary social events in a rural Dominican community, with the objective of understanding differences between in-group and out-group competition in adult and adolescent males. Our analyses indicate: (1) adult and adolescent males do not elevate testosterone when they defeat their friends, but they do elevate testosterone when they defeat outsiders; (2) pre-competition testosterone and cortisol levels are negatively associated with strength of coalitionary ties; and (3) adult males usually elevate testosterone when interacting with adult women who are potential mates, but in a striking reversal, they have lower testosterone if the woman is a conjugal partner of a close friend. These naturalistic studies hint that reciprocity, dampening of aggression, and competition among friends and allies may be biologically embedded in unique ways among humans. (shrink)

Why does the world have the pattern of patriarchy it currently possesses? Why have patriarchal practices and institutions evolved and changed in the ways they have tended to over time in human societies? This paper explores these general questions by integrating a feminist analysis of patriarchy with the central insights of the functionalist interpretation of historical materialism advanced by G. A. Cohen. The paper has two central aspirations: first, to help narrow the divide between analytical Marxism and feminism by redressing (...) the former's neglect of the important role female labor has played, and continues to play, in shaping human history. Second, by developing the functionalist account of historical materialism in order to take patriarchy seriously, we can derive useful insights for diagnosing the emancipatory challenges that women face in the world today. The degree and form of patriarchy present in any particular society is determined by the productive forces it has had at its disposal. According to historical materialism, technological, material, and medical advances that ease the pressures on high fertility rates (such as the sanitation revolution, vaccinations, birth control, and so on) are the real driving forces behind the positive modulations to patriarchy witnessed in the twentieth century. (shrink)

Previous research on warfare in a worldwide sample of societies by Ember and Ember (Journal of Conflict Resolution, 36, 242–262, 1992a) found a strong relationship between resource unpredictability (particularly food scarcity caused by natural disasters) in nonstate, nonpacified societies and overall warfare frequency. Focusing on eastern Africa, a region frequently plagued with subsistence uncertainty as well as violence, this paper explores the relationships between resource problems, including resource unpredictability, chronic scarcity, and warfare frequencies. It also examines whether resource scarcity predicts (...) more resource-taking in land, movable property, and people, as well as the commission of atrocities. Results support previous worldwide results regarding the relationship between resource unpredictability and warfare frequency. Results regarding resource-taking and atrocities are more nuanced and complex. In almost all findings, relationships are generally in opposite directions in nonstate and state societies. In post-hoc analyses, atrocities are significantly more likely to be committed in states than in nonstates. (shrink)

The DSM-III, DSM-IV, DSM-IV-TR and ICD-10 have judiciously minimized discussion of etiologies to distance clinical psychiatry from Freudian psychoanalysis. With this goal mostly achieved, discussion of etiological factors should be reintroduced into the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition. A research agenda for the DSM-V advocated the "development of a pathophysiologically based classification system". The author critically reviews the neuroevolutionary literature on stress-induced and fear circuitry disorders and related amygdala-driven, species-atypical fear behaviors of clinical severity in adult (...) humans. Over 30 empirically testable/falsifiable predictions are presented. It is noted that in DSM-IV-TR and ICD-10, the classification of stress and fear circuitry disorders is neither mode-of-acquisition-based nor brain-evolution-based. For example, snake phobia and dog phobia are clustered together. Similarly, research on blood-injection-injury-type-specific phobia clusters two fears different in their innateness: 1) an arguably ontogenetic memory-trace-overconsolidation-based fear and 2) a hardwired fear of the sight of one's blood or a sharp object penetrating one's skin. Genetic architecture-charting of fear-circuitry-related traits has been challenging. Various, non-phenotype-based architectures can serve as targets for research. In this article, the author will propose one such alternative genetic architecture. This article was inspired by the following: A) Nesse's "Smoke-Detector Principle", B) the increasing suspicion that the "smooth" rather than "lumpy" distribution of complex psychiatric phenotypes may in some cases be accounted for by oligogenic transmission, and C) insights from the initial sequence of the chimpanzee genome and comparison with the human genome by the Chimpanzee Sequencing and Analysis Consortium published in late 2005. Neuroevolutionary insights relevant to fear circuitry symptoms that primarily emerge overconsolidationally are presented. Also introduced is a human-evolution-based principle for clustering innate fear traits. The "Neuroevolutionary Time-depth Principle" of innate fears proposed in this article may be useful in the development of a neuroevolution-based taxonomic re-clustering of stress-triggered and fear-circuitry disorders in DSM-V. Four broad clusters of evolved fear circuits are proposed based on their time-depths: 1) Mesozoic circuits hardwired by wild-type alleles driven to fixation by Mesozoic selective sweeps; 2) Cenozoic circuits relevant to many specific phobias; 3) mid Paleolithic and upper Paleolithic circuits ; 4) Neolithic circuits. More importantly, the author presents evolutionary perspectives on warzone-related PTSD, Combat-Stress Reaction, Combat-related Stress, Operational-Stress, and other deployment-stress-induced symptoms. The Neuroevolutionary Time-depth Principle presented in this article may help explain the dissimilar stress-resilience levels following different types of acute threat to survival of oneself or one's progency. PTSD rates following exposure to lethal inter-group violence are usually 5-10 times higher than rates following large-scale natural disasters such as forest fires, floods, hurricanes, volcanic eruptions, and earthquakes. The author predicts that both intentionally-caused large-scale bioevent-disasters, as well as natural bioevents such as SARS and avian flu pandemics will be an exception and are likely to be followed by PTSD rates approaching those that follow warzone exposure. During bioevents, Amygdala-driven and locus-coeruleus-driven epidemic pseudosomatic symptoms may be an order of magnitude more common than infection-caused cytokine-driven symptoms. Implications for the red cross and FEMA are discussed. It is also argued that hospital phobia as well as dog phobia, bird phobia and bat phobia require re-taxonomization in DSM-V in a new "overconsolidational disorders" category anchored around PTSD. The overconsolidational spectrum category may be conceptualized as straddling the fear circuitry spectrum disorders and the affective spectrum disorders categories, and may be a category for which Pitman's secondary prevention propranolol regimen may be specifically indicated as a "morning after pill" intervention. Predictions are presented regarding obsessive-compulsive disorder and "culture-bound" acute anxiety symptoms. Also discussed are insights relevant to pseudoneurological symptoms and to the forthcoming Dissociative-Conversive disorders category in DSM-V, including what the author terms fright-triggered acute pseudo-localized symptoms. Speculations based on studies of the human abnormal-spindle-like, microcephaly-associated gene, the microcephaly primary autosomal recessive gene, and the forkhead box p2 gene are made and incorporated into what is termed "The pre-FOXP2 Hypothesis of Blood-Injection-Injury Phobia." Finally, the author argues for a non-reductionistic fusion of "distal neurobiology" with clinical "proximal neurobiology," utilizing neurological heuristics. It is noted that the value of re-clustering fear traits based on behavioral ethology, human-phylogenomics-derived endophenotypes and on ontogenomics can be confirmed or disconfirmed using epidemiological or twin studies and psychiatric genomics. (shrink)