Chapter 4, The Science of Adultery Summary and Analysis

Several scientifically rigorous genetic investigations of large populations conclusively demonstrate that roughly 10 percent of human children are not the genetic children of the male parent whom assumes genetic relatedness - in other words, about 10 percent of children are not genetically related to their putative "biological" father; thus, secretive extra-marital sexual unions are in fact exceptionally common among couples who self-identify as exclusively monogamous. Many of these scientific studies were never published because their conclusions were deemed too inflammatory.

For evolutionary reasons, extra-marital sex is approached differently by men than by women. Men can supposedly enjoy extra-marital sex with a minimum of consequences because an impregnated secondary sexual partner can simply be abandoned. On the other hand, women must be highly selective in extra-marital sexual partners to avoid compromise or disclosure. These differing goals...