Social psychologists have found that women prefer to have sex with a “Cad” when considering a brief affair but for longer term relationships they prefer “Dads.” Leading Tyler to ask in an earlier post, Why do women like cads?
Patrick Vlaskovits, a reader, hypothesizes that Cads have better genes than Dads. Patrick writes:
Why is a Cad a Cad? I think it is because: He can be. His genes are so good, so much in demand, that women are willing to mate with him knowing that he might not stick around. Same reason why a Dad is a Dad. He knows if based solely on looks (proxy for gene competition), he will lose to the Cad every time. So, he must compensate for his lower quality genes by investing more resources in the female and offspring.
Symmetry is an important aspect of beauty and has been shown to be a signal of good genes so the theory can be tested by looking at how mating strategies vary with symmetrical features. Psychologists Steven Gangestad and Jeffrey Simpson report that this has been done with birds:
In a recent review of 18 bird species, MÃ¸ller and Thornhill (1997a) have documented an association between extra-pair paternity and the extent to which attractive males engage in direct parental care. Specifically, when the rate of extra-pair paternity is high (and, thus, when males can benefit more from trying to attract extra-pair mates), attractive males perform a smaller proportion of offspring feedings than do less attractive males. Exerting greater extra-pair mating effort should yield larger payoffs for more attractive males, and this is evident in the time they fail to spend engaging in a competing activity: providing direct parental care.
Gangestad and Simpson suggest that the theory also applies to humans:
Over evolutionary history, men who had indicators of genotypic quality should have experienced larger gains in fitness payoffs than men who lacked these indicators. Moreover, men should have evolved to conditionally “decide” to allocate more versus less effort to mating or parenting, depending on the degree to which they possess these features.
Note, however, that the context in which men play the Cad v. Dad strategy, human society, is much more variable than that faced by birds. The Cad strategy will not work well in times and places where extra-marital sex is uncommon. Ever heard of an Amish Cad?