There Is No Simple or Universally Accepted Explanation for the Fact

Multiple Choice

There is no simple or universally accepted explanation for the fact that nearly all cultures ban incest. However, the most accepted explanation for the incest restriction is

A) that isolated social groups are better at survival.
B) a genetically determined attraction for those most different from us.
C) a genetically programmed instinctive horror.
D) that following rules of exogamy is adaptively advantageous.
E) a widespread and well-founded fear of biological degeneration.