References have been made in this book to experiments done with animals. It seems appropriate, therefore, to examine briefly selected data from the literature on animal studies, especially as it may relate to human sexuality. The first reason these studies are significant is that much of the data is indeed relevant to humans, for example, certain hormonal and biochemical findings. We must, however, be cautious in generalizing from animal studies to human behavior. Behavior in a lower organism that appears similar to human behavior is not necessarily identical to the human behavior. Such a similarity can be misleading if not examined critically. An animal behavior which is similar to a human behavior can have a very different origin and may be influenced by one or more of a variety of different biochemical, hormonal, neurological, psychosocial, and behavioral variables. For example, sexual behaviors between members of the same sex have been observed in many species. To use such examples as models of human homosexuality, however, simply because of the observed similarities in overt behavior and without consideration of possible origins and other variables, is clearly inappropriate.
A second reason for discussing sexual behaviors in lower organisms is to bring an evolutionary perspective to the study of sexuality. Some similarities between related species may be a function of their common phylogenetic ancestry. As Beach (1976) has stated, "Man is no more a naked ape than chimpanzees are hairy people, but he is a mammal and a primate and as such shares certain physical and behavioral characteristics with other members of his class and order" .
Men's Health-Erectile Dysfunction