On the 24th of January, Secretary of Defense Leon Panetta lifted the ban on women serving in combat roles in the military. This decision was not without controversy. Reformers argue that lifting the ban simply acknowledges what has become a practical reality. In recent wars, women have already been called into combat situations as support technicians, medics, drivers, and specialists. The difference is primarily that taking on combat duties would allow women to receive promotion and recognition for their valor. However, critics are still quite vocal in their assessments, questioning the physical and psychological abilities of women to perform their duties and the effects gender integration might have on the interpersonal dynamics within the military . These arguments draw on one of the most controversial fields within the social sciences: evolutionary psychology.
Evolutionary psychology studies how natural selection has guided the development of human cognition and behavior. Just like our bodies, our minds were subjected to natural selection, whereby instincts and dispositions that helped our ancestors survive and reproduce were passed down to us, and still influence the way we think and behave.
In an article published in October of 2012, Psychologist Kingsley Browne argues that innate, evolved gender differences make exclusively male coalitions more cohesive, stable, and effective than mixed gender groups in high stress combat situations. Although Browne’s claim draws data from a broad range of studies, it also reveals some of the problems with using evolutionary psychology to make policy recommendations . Opponents of integrated combat argue that the presence of women undermines the social dynamics that allow traditionally male combat units to function as a cohesive unit.
The argument itself is simple. First, Browne discusses many of the gender differences that have been documented in psychological research. On the whole, the average man is better suited for combat than the average woman. Physically, men tend to have more upper body strength and endurance. Men also tend to score higher on measures of aggression and pain tolerance. Meanwhile, women typically score higher on measures of empathy and risk aversion—characteristics that inhibit combat performance .
It is necessary to understand that these results are describing populations, not the individuals within them. As such, they do not constitute a compelling argument for discrimination. After all, if an individual is able to meet the physical and psychological requirements for a job, it shouldn’t matter if he or she comes from a group where these characteristics are less common.
What evolutionary psychologists are concerned with, however, is the influence these general trends may have had on the evolution of group dynamics. Imagine the prehistoric man. He would have been more likely to come back alive and victorious from conflicts if he made generalizations and used stereotypes when selecting comrades. Research has demonstrated that decisions about who we trust are spontaneous, non-rational, and very sensitive to context. As such, for men in particular, a preference for masculine characteristics in times of stress might have been valuable .
This conclusion is supported indirectly by studies of gender differences in intergroup dynamics. Historically, men tended to fight in all male coalitions, and even mixed gender groups show a preference for male leadership in conditions of intergroup conflict. Moreover, men tend to have an easier time identifying with a group and taking risks on behalf of that group. They are also better at excluding and demonizing outsiders, and take greater pride in proving themselves members of the group .
At the scientific level, this may be true. Men generally seem to have difficulty trusting women who try to fill traditionally masculine roles. Although there is evidence that social conditioning plays a significant role in this, Browne argues that this is partially an innate preference. Men prefer masculine characteristics in the context of conflict the same way they prefer indicators of health and fertility in the context of romance and sexuality. 
However, even if men do have these partially innate preferences, research has shown that people hold many, many implicit prejudices that affect who we trust and identify with. Accent and language are examples of this . Racial prejudices also continue to dog us, despite our best efforts. It is certainly plausible that these prejudices are part of our evolutionary heritage, from an age when our ancestors’ survival depended on their ability to recognize members of enemy tribes. Should we not then re-segregate our battalions, since our prehistoric ancestors certainly did not fight alongside members of other races?
Any suggestion like this would be rightfully dismissed and condemned.
The issue is ultimately the adaptability of the human mind. The great innovation in human evolution was a brain that developed over the course of the individual’s lifetime, allowing new behaviors and adaptations to arise without the long and costly process of Darwinian evolution.
In adapting to the conditions of modern warfare, a military culture based around the traditional “band of brothers” creates problems. Studies show, for example, that exclusively male coalitions tend to enforce a great deal homogeneity through ritual hazing and the demonization of outsiders . These social dynamics, in addition to making military groups hostile to women and to their civilian allies, can negatively impact unit efficacy. Highly homogenous groups are especially susceptible to “groupthink,” where demands for loyalty and conformity in times of crisis cause the group to make faulty analysis and be highly committed to prior courses of action. In a modern, prolonged engagement, with complex and obscure objectives that can only be achieved through cooperation with non-military personnel, such groups would actually be at a significant disadvantage [4, 5]
These problems, research shows, are far less prevalent in groups that have “task based” cohesion, where individuals are not committed to each other, but share a commitment to the group’s collective goal .
It may take many years for the military culture to become more inclusive and accommodating for female personnel. But human cultures have accommodated far greater changes in the past, and will likely be faced with greater transitions in the future. Despite the claims of many, evolutionary psychology is ultimately a poor guide for policy. It perpetually bumps into the naturalistic fallacy: that what is natural is what is right. Evolutionary psychology is also conservative. It explains the world as we see it, but offer little insight into how it could be different.
This is not to say that evolutionary psychology is without value. Within the realm of the sciences, considering the forces that shaped human evolution can reveal new hypotheses to test and unify otherwise disconnected findings. Practically all psychologists acknowledge that evolutionary processes shaped us, and without accounting for them, our understanding of the human mind could not be complete. It is a valuable guide for research. However, when used to guide policy, evolutionary psychology understates the human capacity for change.
1. Mackenzie, Megan. 2006. ”Let Women Fight: Ending the U.S. Military’s Female Combat Ban.” Foreign Affairs, November/December 2012 (Updated Jan 23, 2013). http://www.foreignaffairs.com/articles/138200/megan-h-mackenzie/let-women-fight?page=show
2. Browne, Kingsley. 2012. “Band of Brothers or Band of Siblings?” In The Oxford Handbook of Evolutionary Perspectives on Violence, Homicide, and War, ed. Todd K. Shackelford et al., 372-393. Oxford: Oxford University Press.
3. Cohen, Emma. 2012. “The evolution of tag-based cooperation in humans: The case for accent.” Current Anthropology, 53: 588-605.
4. Kora-Kakabads, Andrew et al. 1998. “Demographics and leadership philosophy: exploring gender differences.” The Journal of Management Development, 17: 351-388.
5. Janis, Irving. 1982. Victims of Groupthink. Boston: Houghton-Mifflin.
Image Credit: Wikimedia Commons: “The US Army—Composure Under Pressure” http://upload.wikimedia.org/wikipedia/commons/a/af/Flickr_-_The_U.S._Army_-_Composure_Under_Pressure.jpg
Image Credit: Wikimedia Commons: “Women’s Veterans Monument Rock Beach” http://commons.wikimedia.org/wiki/File:Women_Veterans_Monument_Rock_Beach_jeh.jpg
Daniel is a third year student at the University of Chicago majoring in Psychology and the History and Philosophy of Science.