W War societies, there has been no historically documented case of organized fighting and killing Francis T. McAndrew by groups of women against other groups of Knox College, Galesburg, IL, USA women. The consistency with which males are the organizers and perpetrators of group conflict has led many scholars to conclude that the male Synonyms propensity for group violence is rooted in more than the learning of culturally prescribed gender Battle; Combat; Conflict; Hostilities; Invasion; roles. Most evolutionary psychologists believe Raiding; Warfare that the roots of warfare can be traced to the competition between males for status and access to women (McAndrew 2017). Definition “War” is an armed conflict between nations Male Competition for Mates Is Intense or organized groups such as tribes, gangs, kin groups, or political factions. The adaptive problems faced by men and women throughout history were quite different, and aggression proved to be a more adaptive response Introduction for males than for females. Sexual competition for mates has always been more intense among males It is obvious that warfare is a highly cooperative than among females, especially in the polyga- activity that requires good communication and mous societies that appear to have been typical cooperation with allies and intelligent self-control in the prehistoric human world. (Tooby and Cosmides 2010), but there has been a The stakes were very high for men in this long-standing disagreement among historians and environment, as the winners of this competition social scientists regarding the origins of human would come away with the greatest number of warfare. In the last couple of decades, evolution- women (and the most desirable women). The ary scientists have brought yet another perspec- losers ran the risk of genetic annihilation by their tive to bear on this issue. failure to successfully win the status and resources The first point to be emphasized is the extent to necessary to attract mates. Historically, powerful which war is almost exclusively a male activity. In men have always enjoyed greater sexual access to spite of the diversity to be found across human women than men lower in the pecking order, and # Springer International Publishing AG, part of Springer Nature 2018 T. K. Shackelford, V. A. Weekes-Shackelford (eds.), Encyclopedia of Evolutionary Psychological Science, https://doi.org/10.1007/978-3-319-16999-6_2235-1 2 War violence, including war, can often be traced to this Many studies demonstrate that people who grim struggle for status and mates among men. sacrifice for the group by engaging in costly altru- Violence committed against the right people at istic activities do in fact achieve elevated social the right time has commonly been a ticket to social status, respect, and recognition as a result of their success. For example, among the Yanomamo of public selflessness (McAndrew and Perilloux South America, men who had killed other men, 2012a, b; Willer 2009). For a costly signal to be especially during wars and skirmishes with other effective, it must honestly convey valuable infor- villages, acquired significantly more wives than mation about the individual sending the signal, men who had not yet killed anyone (Chagnon and it must be impossible to fake. No researchers 2013). Because having killed someone in war suggest that heroes consciously sit down and cal- was usually good for one’s reputation, many soci- culate all of the benefits that will come their way if eties developed ceremonies for recognizing such they survive the heroic action. Rather, it is thought accomplishments. In modern societies, these take that such impulses have been selected for because the form of prestigious awards such as the Con- heroic behavior has provided competitive advan- gressional Medal of Honor in the United States, tages for men throughout human history. and many countries have national holidays to celebrate the heroism of those who have fought and/or died in wars. Have Men Evolved to Make War? To insure that public recognitions of valor dur- ing war serve as honest signals of heroic behavior, Dutch psychologist Mark van Vugt proposed the sanctions may be brought to bear against individ- male warrior hypothesis as a way of explaining uals who falsely claim to have attained military the results of research demonstrating that men honors. For example, in the United States, the show stronger group identification and more “Stolen Valor Act of 2005” was signed into law cooperation with ingroup members than do by President George W. Bush to prohibit women during times of threat from outside groups the unauthorized wear, sale, or manufacture of (Van Vugt et al. 2007). His theory suggests that military decorations and medals. This law was men have evolved a predisposition to engage in extended by the “Stolen Valor Act of 2013” collective cooperative aggression against signed into law by President Barack Obama. The outgroups, a tendency that has likely been 2013 law makes it a crime for a person to fraud- strongly reinforced through culture traditions ulently claim to have received military medals and socialization. Puts (2010) has also pointed and decorations. out that men tend to form more hierarchical same-sex coalitional groups than do women and that they are more likely than women to make Could War Heroism Be Adaptive? strong ingroup/outgroup distinctions that result in the dehumanization of outgroup members (Buss 2015). Evolutionary psychologists believe that even A team of European psychologists explored apparently selfless impulses such as volunteering the proposition that war provides an arena for to fight in a war must provide some adaptive men to compete and impress both their male rivals advantage for individuals. Costly signaling theory and females who might be potential mates (Rusch (Bereczkei et al. 2010; Bliege Bird et al. 2005; et al. 2015). In one study, they found that Grafen 1990; McAndrew 2002; Zahavi 1977) 464 American men who had won the Medal of suggests that conspicuous war heroism may be a Honor during World War II eventually had more way for individuals to advertise desirable personal children than other US service men who had not qualities that increase the likelihood that they will been so heroically distinguished. This is consis- be chosen as a mate or an ally and be positioned tent with the idea that heroism gets rewarded with for access to future resources. greater reproductive success. War 3 In a second study, 92 women rated the sexual For the 5-year period from 2010 to 2014, the attractiveness of men who had behaved heroically Darwin Award winners were skewed toward in war as being higher than that of soldiers who men by a margin of 38–5, with two of the five had served but not been identified as heroes. Tell- women who made the list getting there by being ingly, women did not show this increased attrac- talked into having sex with men under less than tion toward men who had behaved heroically in rational circumstances (DarwinAwards.com). sports or business situations. A third study Men are sensitive to signals that advertise the revealed that behaving heroically in war does not physical strength, fighting ability, and aggressive increase the attractiveness of female war heroes to inclinations of other men (Sell et al. 2009, 2010) men. In summary, heroism in time of war is sexier and actively assess the likely outcomes of violent than any other kind of heroism but only for men. encounters between themselves and other men Similarly enhanced access to females has been (Fox 1997). Today, the proliferation of sports documented for males who join violent street undoubtedly developed as a constructive alterna- gangs (Palmer and Tilley 1995). tive for dealing with the proclivities of young Young men are particularly concerned with males that evolved in a very different time. In a status and heroic opportunities for sound evolu- legally sanctioned gladiatorial arena, young men tionary reasons. In early human societies, compet- compete to exhibit the same skills – throwing, itive success or failure in early adulthood clubbing, running, wrestling, tackling, and eye- determined a man’s standing in a social group hand coordination – that would have made them for the rest of his life. It wasn’t possible to simply successful fighters and hunters in the ancestral hit the “reset” button and join another group, environment. The popular appeal of spectator so what happened during the teen years mattered sports, especially for men, probably occurs at a lot. For this reason, high-risk competition least in part because it taps into an innate interest between young males provided an opportunity in the physical capabilities of other men. for “showing off” the abilities needed to acquire The idea that men use war as a way of compet- resources, exhibit strength, and meet any chal- ing with each other to impress women has lenges to one’s status (Iredale et al. 2008; clearly been around for quite some time. For McAndrew 2009). Consequently, heroic or even example, the Sioux warrior Rain in the Face recklessly daredevil behavior was rewarded with once commented on the fact that the presence of status and respect – assuming, of course, that the women in a war party caused his warriors to vie young man survived the ordeal. Displaying hero- with one another more intensely in displaying ism in time of war was a primary way of their valor (Philbrick 2010). accomplishing these goals. Hence, it should not be surprising that historical data confirm that the proportion of a population made up of What Are the Necessary Precursors to young men is one of the best predictors of when War? a society is most likely to go to war (Mesquida and Wiener 1996). In addition to the aforementioned prerequisite The relentlessness of risky, aggressive behav- of having a sufficient number of young men in ior by young males has prompted Wilson and a group who are able to fight, evolutionary Daly (1985) to label this behavioral tendency the social scientists have long recognized that a “Young Male Syndrome.” number of other conditions predict a group’s The results of the annual “Darwin Awards” willingness to wage war.