The male warrior hypothesis (MWH) is an evolutionary psychology hypothesis by Professor Mark van Vugt which argues that human psychology has been shaped by between-group competition and conflict. Specifically, the evolutionary history of coalitional aggression between groups of men may have resulted in sex-specific differences in the way outgroups are perceived, creating ingroup vs. outgroup tendencies that are still observable today. [1] [2]
Violence and aggression are universal across human societies, and have likely been features of human behavior since prehistory. Archaeologists have found mass graves dating to the late Pleistocene and early Holocene that contain primarily male skeletons showing signs of blunt force trauma, indicating the cause of death was by weapons used in combat. [3]
Violence among humans occurs in distinct patterns, differing most obviously by sex. Ethnographic findings and modern crime data indicate that the majority of violence is both perpetrated by and targeted at males, and males are the most likely to be victims of violence. This male-male pattern of violence has been observed so repeatedly and in so many cultures that it may qualify as a human universal. [4]
Humans are a social species with a long history of living in tribal groups. The psychological mechanisms that evolved to handle the complexities of group living have also created heuristics for quickly categorizing others as ingroup or outgroup members, with different behavioral strategies for each: treat ingroup members (those in one’s own group) favorably, and react to outgroup members (those who belong to a different group) with fear and aggression. These tendencies arise with little motivation, and have been provoked over superficial groups in lab studies—for example, by showing paintings to participants and creating groups based on which painting participants prefer. [5] [6]
The male warrior hypothesis suggests that the ease with which individuals discriminate against others is an adaptation resulting from a long history of being threatened by outgroup males, who are in competition for resources. [1]
The MWH argues that the sex differences in attitudes towards outgroup members may be a result of the different reproductive strategies used by males and females—specifically, the greater competition among males for mates. In mammals, males and females have distinct reproductive strategies based on the physiology of reproduction. Because females gestate, birth, feed, and invest more overall resources in each of their offspring, they are more selective with their mates but have greater certainty of being able to reproduce. [1] [2]
Males, in contrast, can mate at a very low energetic cost once they have found a partner, but are only able to attract a female if they have physical or social characteristics that can be converted into resources—e.g., territory, food resources, status, power, or influence—or the strength and alliances to coerce females to mate. [1] [2] As a result, there is typically much greater variability in the reproductive success of males within a species and higher competition among males for mates. The strongest, best adapted, and most powerful males may have a harem, while less fit males never reproduce. [7]
For more details on this topic, see Trivers' theory of parental investment.
The male warrior hypothesis predicts that because males may have historically remained in the groups in which they were born rather than moving away at adulthood (see patrilocality), they have a higher overall relatedness to their group than the female members, who would have moved to their new husbands’ group upon marriage. [1] [2] Males may have a stronger interest in defending their group, and will be more likely to act aggressively towards outgroup males they encounter who may be attempting to steal resources or weaken the group with violence.
For men at risk of never finding a mate, the fitness benefit to engaging in aggressive, violent behavior could outweigh the potential costs of fightings, especially if fighting alongside a coalition. Furthermore, the groups with more individuals who formed coalitions and acted altruistically to in-group members but aggressively to outgroup members would prosper [8] (see multi-level selection).
Consistent with the expectations of the male warrior hypothesis, several studies have shown more ethnocentric and xenophobic [9] beliefs and behaviors among men (compared to women), including the more frequent use of dehumanizing speech to describe outgroup members; [10] stronger identification with their groups; [10] greater cooperation when faced with competition from another group; [11] a greater desire to engage in war when presented with images of attractive (but not unattractive) members of the opposite sex; [12] greater overall rates of male-male competition and violence (as shown in violent crime and homicide statistics [13] ); and larger body size correlating with quicker anger responses. [14]
Studies have also tested the responses of women to outgroups, and have shown that women are most likely to fear outgroup males during the periovulatory phase of the menstrual cycle, when fertility is at its peak. [15] Women also have more negative responses around peak fertility when the males belong to an outgroup that the woman associates with physical formidability, even if the group was constructed in the lab. [16] Overall, women who feel most at risk of sexual coercion are more likely to fear outgroup males, [15] [17] which aligns with the predictions of the MWH.
In studies of prepared learning, conditioned fear responses to images of outgroup males were far more difficult to extinguish than conditioned fear responses to outgroup females or ingroup members of either sex, as measured by conductivity tests of perspiration on the skin. These results held true whether the participant was male or female. [17] Because the neural circuitry for fear responses are more developed towards stimuli that have posed a larger threat for most of human history (snakes and spiders, for example, which were dangers frequently encountered by foragers [18] ), these findings suggest that outgroup males may have been more of a threat to physical safety than outgroup women or ingroup members, supporting the male warrior hypothesis. [1] [2]
It is hypothesized that sport began as a way for men to develop the skills needed in primitive hunting and warfare, and later developed to act primarily as a lek where male athletes display and male spectators evaluate the qualities of potential allies and rivals. This hypothesis is supported by the observation that the most popular modern male sports require the skills needed for success in male-male physical competition and primitive hunting and warfare, and that champion male athletes obtain high status and thereby reproductive opportunities in ways that parallel those gained by successful primitive hunters and warriors. [19] There is evidence that male and female athletes generally differ in their motivation in sports, specifically their competitiveness and risk taking, in accordance with the spectator lek hypothesis. [20]
The male warrior hypothesis proposes that men must engage in maximally effective intra-group cooperation. Post-conflict affiliation between opponents is proposed to facilitate future cooperation. Regarding sports matches as a proxy for intra-group conflict, a study found that unrelated human males are more predisposed than females to invest in post-conflict affiliation that is expected to facilitate future intra-group cooperation. [21]
Coalitionary violence has also been observed in social species besides humans, including other primates. Chimpanzee (Pan troglodytes) males demonstrate similar violent behavior: groups of males form coalitions that patrol the borders of their territory and attack neighboring bands. Chimpanzees also have patrilocal living patterns, which aid with forming close coalitions, as all males are likely kin. [22]
A study of 72 species of group-living mammals found that males are more involved than females in inter-group conflict where male fitness is limited by access to mates whereas female fitness is limited by access to food and safety. [23]
Aggression is hostile and antagonistic behavior, often with the intent to cause harm, although it can be channeled into creative and practical outlets for some. It may occur either reactively or without provocation. In humans, aggression can be caused by various triggers. For example, built-up frustration due to blocked goals or perceived disrespect. Human aggression can be classified into direct and indirect aggression; whilst the former is characterized by physical or verbal behavior intended to cause harm to someone, the latter is characterized by behavior intended to harm the social relations of an individual or group.
Prejudice can be an affective feeling towards a person based on their perceived group membership. The word is often used to refer to a preconceived evaluation or classification of another person based on that person's perceived personal characteristics, such as political affiliation, sex, gender, gender identity, beliefs, values, social class, age, disability, religion, sexuality, race, ethnicity, language, nationality, culture, complexion, beauty, height, body weight, occupation, wealth, education, criminality, sport-team affiliation, music tastes or other perceived characteristics.
Group dynamics is a system of behaviors and psychological processes occurring within a social group, or between social groups. The study of group dynamics can be useful in understanding decision-making behaviour, tracking the spread of diseases in society, creating effective therapy techniques, and following the emergence and popularity of new ideas and technologies. These applications of the field are studied in psychology, sociology, anthropology, political science, epidemiology, education, social work, leadership studies, business and managerial studies, as well as communication studies.
The out-group homogeneity effect is the perception of out-group members as more similar to one another than are in-group members, e.g. "they are alike; we are diverse". Perceivers tend to have impressions about the diversity or variability of group members around those central tendencies or typical attributes of those group members. Thus, outgroup stereotypicality judgments are overestimated, supporting the view that out-group stereotypes are overgeneralizations. The term "outgroup homogeneity effect", "outgroup homogeneity bias" or "relative outgroup homogeneity" have been explicitly contrasted with "outgroup homogeneity" in general, the latter referring to perceived outgroup variability unrelated to perceptions of the ingroup.
In-group favoritism, sometimes known as in-group–out-group bias, in-group bias, intergroup bias, or in-group preference, is a pattern of favoring members of one's in-group over out-group members. This can be expressed in evaluation of others, in allocation of resources, and in many other ways.
Sex differences in crime are differences between men and women as the perpetrators or victims of crime. Such studies may belong to fields such as criminology, sociobiology, or feminist studies. Despite the difficulty of interpreting them, crime statistics may provide a way to investigate such a relationship from a gender differences perspective. An observable difference in crime rates between men and women might be due to social and cultural factors, crimes going unreported, or to biological factors for example, testosterone or sociobiological theories). The nature of the crime itself may also require consideration as a factor.
In psychology and other social sciences, the contact hypothesis suggests that intergroup contact under appropriate conditions can effectively reduce prejudice between majority and minority group members. Following WWII and the desegregation of the military and other public institutions, policymakers and social scientists had turned an eye towards the policy implications of interracial contact. Of them, social psychologist Gordon Allport united early research in this vein under intergroup contact theory.
Social dominance theory (SDT) is a social psychological theory of intergroup relations that examines the caste-like features of group-based social hierarchies, and how these hierarchies remain stable and perpetuate themselves. According to the theory, group-based inequalities are maintained through three primary mechanisms: institutional discrimination, aggregated individual discrimination, and behavioral asymmetry. The theory proposes that widely shared cultural ideologies provide the moral and intellectual justification for these intergroup behaviors by serving to make privilege normal. For data collection and validation of predictions, the social dominance orientation (SDO) scale was composed to measure acceptance of and desire for group-based social hierarchy, which was assessed through two factors: support for group-based dominance and generalized opposition to equality, regardless of the ingroup's position in the power structure.
Social identity is the portion of an individual's self-concept derived from perceived membership in a relevant social group.
Infrahumanisation is the tacitly held belief that one's ingroup is more human than an outgroup, which is less human. The term was coined by Jacques-Philippe Leyens and colleagues in the early 2000s to distinguish what they argue to be an everyday phenomenon from dehumanization associated with extreme intergroup violence such as genocide. According to Leyens and colleagues, infrahumanisation arises when people view their ingroup and outgroup as essentially different and accordingly reserve the "human essence" for the ingroup and deny it to the outgroup. Whether a "subhuman" classification means "human but inferior" or "not human at all" may be academic, as in practice it corresponds to prejudice regardless.
Realistic conflict theory (RCT), also known as realistic group conflict theory (RGCT), is a social psychological model of intergroup conflict. The theory explains how intergroup hostility can arise as a result of conflicting goals and competition over limited resources, and it also offers an explanation for the feelings of prejudice and discrimination toward the outgroup that accompany the intergroup hostility. Groups may be in competition for a real or perceived scarcity of resources such as money, political power, military protection, or social status.
Self-categorization theory is a theory in social psychology that describes the circumstances under which a person will perceive collections of people as a group, as well as the consequences of perceiving people in group terms. Although the theory is often introduced as an explanation of psychological group formation, it is more accurately thought of as general analysis of the functioning of categorization processes in social perception and interaction that speaks to issues of individual identity as much as group phenomena. It was developed by John Turner and colleagues, and along with social identity theory it is a constituent part of the social identity approach. It was in part developed to address questions that arose in response to social identity theory about the mechanistic underpinnings of social identification.
Sexual selection in humans concerns the concept of sexual selection, introduced by Charles Darwin as an element of his theory of natural selection, as it affects humans. Sexual selection is a biological way one sex chooses a mate for the best reproductive success. Most compete with others of the same sex for the best mate to contribute their genome for future generations. This has shaped human evolution for many years, but reasons why humans choose their mates are not fully understood. Sexual selection is quite different in non-human animals than humans as they feel more of the evolutionary pressures to reproduce and can easily reject a mate. The role of sexual selection in human evolution has not been firmly established although neoteny has been cited as being caused by human sexual selection. It has been suggested that sexual selection played a part in the evolution of the anatomically modern human brain, i.e. the structures responsible for social intelligence underwent positive selection as a sexual ornamentation to be used in courtship rather than for survival itself, and that it has developed in ways outlined by Ronald Fisher in the Fisherian runaway model. Fisher also stated that the development of sexual selection was "more favourable" in humans.
The ultimate attribution error is a type of attribution error which describes how attributions of outgroup behavior are more negative than ingroup behavior. As a cognitive bias, the error results in negative outgroup behavior being more likely to be attributed to factors internal and specific to the actor, such as personality, and the attribution of negative ingroup behavior to external factors such as luck or circumstance. The bias reinforces negative stereotypes and prejudice about the outgroup and favouritism of the ingroup through positive stereotypes. The theory also extends to the bias that positive acts performed by ingroup members are more likely a result of their personality.
An implicit bias or implicit stereotype is the pre-reflective attribution of particular qualities by an individual to a member of some social out group.
The imagined contact hypothesis is an extension of the contact hypothesis, a theoretical proposition centred on the psychology of prejudice and prejudice reduction. It was originally developed by Richard J. Crisp and Rhiannon N. Turner and proposes that the mental simulation, or imagining, of a positive social interaction with an outgroup member can lead to increased positive attitudes, greater desire for social contact, and improved group dynamics. Empirical evidence supporting the imagined contact hypothesis demonstrates its effectiveness at improving explicit and implicit attitudes towards and intergroup relations with a wide variety of stigmatized groups including religious minorities, the mentally ill, ethnic minorities, sexual minorities, and obese individuals. Researchers have identified a number of factors that influence the effectiveness of the imagined contact hypothesis including vividness of the imagery and how typical the imagined outgroup individual is. While some researchers question the effectiveness of the imagined contact hypothesis, empirical evidence does suggest it is effective at improving attitudes towards outgroups.
Intergroup anxiety is the social phenomenon identified by Walter and Cookie Stephan in 1985 that describes the ambiguous feelings of discomfort or anxiety when interacting with members of other groups. Such emotions also constitute intergroup anxiety when one is merely anticipating interaction with members of an outgroup. Expectations that interactions with foreign members of outgroups will result in an aversive experience is believed to be the cause of intergroup anxiety, with an affected individual being anxious or unsure about a number of issues. Methods of reducing intergroup anxiety and stress including facilitating positive intergroup contact.
Intergroup relations refers to interactions between individuals in different social groups, and to interactions taking place between the groups themselves collectively. It has long been a subject of research in social psychology, political psychology, and organizational behavior.
In social psychology, a metastereotype is a stereotype that members of one group have about the way in which they are stereotypically viewed by members of another group. In other words, it is a stereotype about a stereotype. They have been shown to have adverse effects on individuals that hold them, including on their levels of anxiety in interracial conversations. Meta-stereotypes held by African Americans regarding the stereotypes White Americans have about them have been found to be largely both negative and accurate. People portray meta-stereotypes of their ingroup more positively when talking to a member of an outgroup than to a fellow member of their ingroup.
An empathy gap, sometimes referred to as an empathy bias, is a breakdown or reduction in empathy where it might otherwise be expected to occur. Empathy gaps may occur due to a failure in the process of empathizing or as a consequence of stable personality characteristics, and may reflect either a lack of ability or motivation to empathize.
