Who's more likely to be unfaithful: smart or dumb people?

There is a tendency among people who take IQ seriously to believe that greater morality comes with intelligence.  While smarts enable a person to see more clearly long-term consequences of his actions and to understand moral systems more deeply, I'm skeptical that IQ is related to the emotional component of morality.  I suspect smart people are just as cold-blooded as the unintelligent.

Let's focus on one type of immorality: cheating on your spouse.  The General Social Survey asked adults, "Have you ever had sex with someone other than your husband or wife while you were married?"  Here are the answers by IQ level for whites and blacks (samples = 9,391 and 1,410):


Whites

Blacks

For both groups, the risk of infidelity rises with IQ.  Perhaps smarter people have a greater ability to attract partners.  Perhaps they have more social opportunities, or think they are better at fooling their partners. Whatever the case, this data makes bright people look like jerks.