So hundreds of thousands of years ago, males hunted alone for days in the thick jungles, looking to thump something on the head. Females stayed behind with the offspring in the jungle clearing, and collaborated with other females who stayed behind. As a consequence, males became more dominant, while females became more collaborative.
This difference in behavior may help to explain psychologist Carl Jung’s idea that we all possess two types of personalities: a male animus and a feminine anima. One is often just more prominent than the other. Males developed more dominant and aggressive behaviors[i]. These are driven by a Y chromosome that leads to the production of more testosterone[ii]. Testosterone made males more competitive[iii], less collaborative[iv], less concerned about the welfare of others[v], and more oriented to solve problems alone[vi]. Testosterone also explains why 96 percent of all homicides today are committed by males[vii].
Females on the other hand seem to be more driven by the hormone oxytocin that, combined with other hormones, orient them towards more social behaviors[viii]. They also tend to be more emotional: it’s an increased sensitivity to danger which helps to guard against threats to their offspring. Females are more concerned with the welfare of others, collaborate more, are more altruistic[ix], more empathetic[x], show more trust[xi] and reciprocate others’ gestures more[xii]. That need for collaboration is why women go to the bathroom together and men are left scratching their heads at the dinner table asking themselves silently why[xiii].
Men and women are different because over time they simply adapted to the needs of their environment.
[i] Mazur, Allan, and Alan Booth. “Testosterone and dominance in men.” Behavioral and brain sciences 21.3 (1998): 353-363.
[ii] Carlier, Michèle, et al. “Y chromosome and aggression in strains of laboratory mice.” Behavior genetics 20.1 (1990): 137-156.
[iii] Gneezy, Uri, Muriel Niederle, and Aldo Rustichini. “Performance in competitive environments: Gender differences.” The Quarterly Journal of Economics 118.3 (2003): 1049-1074.
[iv] Bozeman, Barry, and Monica Gaughan. “How do men and women differ in research collaborations? An analysis of the collaborative motives and strategies of academic researchers.” Research policy 40.10 (2011): 1393-1402.
[v] Zethraeus, Niklas, et al. “A randomized trial of the effect of estrogen and testosterone on economic behavior.” Proceedings of the National Academy of Sciences 106.16 (2009): 6535-6538.
[vi] Wright, Nicholas D., et al. “Testosterone disrupts human collaboration by increasing egocentric choices.” Proc. R. Soc. B 279.1736 (2012): 2275-2280.
[vii] United Nations Office on Drugs and Crime. Global study on homicide 2013: trends, contexts, data. UNODC, 2013.
[viii] Campbell, Anne. “Attachment, aggression and affiliation: the role of oxytocin in female social behavior.” Biological psychology 77.1 (2008): 1-10.
[ix] Eckel, Catherine C., and Philip J. Grossman. “Are women less selfish than men?: Evidence from dictator experiments.” The economic journal 108.448 (1998): 726-735.
[x] Singer, Tania, et al. “Empathy for pain involves the affective but not sensory components of pain.” Science 303.5661 (2004): 1157-1162.
[xi] Croson, Rachel, and Nancy Buchan. “Gender and culture: International experimental evidence from trust games.” The American Economic Review 89.2 (1999): 386-391.
[xii] Chaudhuri, Ananish, and Lata Gangadharan. “Gender differences in trust and reciprocity.” (2003).
[xiii] Van den Berghe, Pierre L. Race (Racism). John Wiley & Sons, Ltd, 1967.