Gender Differences

Man and Woman, Casual Sex and Jealousy: Insight from the Field of Evolutionary Psychology 'Our modern skulls house a stone age mind." Cosmides and Tooby, 1997 If questioned today, many people might agree with what seems to be an illogical coupling of statements: (1) A man is more likely than his female mate to feel comfortable about having casual sex with multiple partners, but (2) the same man is likely to feel jealous about his mate having sex with someone else.

Yet, when the underlying causes for a male's apparently inconsistent behavior are explored from the perspective of evolutionary psychology, a logical explanation emerges. Evolutionary psychology is a branch of study focused on the problems and stress factors that ancestors of humans faced, the "psychological mechanisms" that natural selection developed to address these problems and stresses, and the ways in which these ancient mechanisms work today (Crawford and Anderson, 1989, cited in Crawford and Salmon, 2004).

Evolutionary psychology focuses on those "affects, cognitions and behaviors" which helped ancestors of humans to solve "some adaptive problem in the ancestral environment" (Kruger, 2002). To arrive at an explanation for a man's tendency to feel more comfortable about having casual sex with multiple partners than does his female mate, the evolutionary psychologist might look to the gametes produced by males and females. Women produce only a few, but energy-rich, gametes (i.e.

eggs), into which they invest a significant amount of physical resources and time from conception through birth and nursing. A woman requires stability to be successful in this endeavor. She is careful in her selection of a mate who can offer the protection and support she needs, focusing on quality over quantity in her mate. A man, on the other hand, produces many, but energy-poor, gametes (i.e. sperm). He has much less of a physical investment in his offspring.

A man, unlike a woman, focuses on quantity of mates rather than relationship quality because, if he has multiple mates, he increases the odds that he will father numerous offspring, thereby helping to ensure the transmission of his genes to successive generations.

(Looy, 2001; Wright, 1994) From the perspective of evolutionary psychology, the desire of the man to maximize chances of transmitting his genes to future generations when compared to the woman's desire for stability helps to explain why a man may feel more comfortable about having casual sex with multiple partners than does his female mate.

Evolutionary psychologists seeking to explain why the same man is likely to feel jealous about his mate having sex with someone else (despite his own willingness to do so) would again look at the differences between men and women. Actually, both men and women experience jealousy. Some contend that jealousy may have provided a "fitness advantage" to the ancestors of humans (Harris, 2004). Although both men and women experience jealousy, the predominant types of jealousy they experience are different.

A woman's jealousy focuses on the emotional infidelity of her mate as she is primarily concerned about losing her source of protection and support to another woman thereby threatening her stability.

On the other hand, a man's jealousy focuses on sexual infidelity, as this is the "greatest genetic threat he faces." (Wright, 1994) Of course, both men and women can feel both types of jealousy; however, this and the preceding contributions from the field of evolutionary psychology help to explain why the same man could be more likely than his female mate to feel comfortable about having casual sex with multiple partners while feeling jealous about his mate having sex with someone else.

The primary strength of the explanation offered by evolutionary psychology is that it furnishes a logical reason for a common form of illogical behavior which may defy alternative explanation. With such an explanation, people experiencing the behaviors may be better positioned to understand themselves and.