Evidence of neuroandrogenic etiology of sex roles from a combined analysis of human, nonhuman primate and nonprimate mammalian studies

Abstract

To explore the question of whether or not androgenic influences upon brain functioning constitute significant causes of sex differences in human behavior, the present report compares research based upon studies of humans, nonhuman primates and nonprimate mammals. The major assumption underlying the approach was as follows: if similar average sex differences in behavior existed for humans and nonhumans alike, and could be shown to be due to the effects of neuroandrogenic factors in nonhumans, one could infer that neuroandrogenic factors are a likely cause of human sex differences in such behavior as well. Twelve behavior patterns were found to exhibit similar average sex differences in humans as in a number of nonhuman species. Evidence surrounding the causes of these behavior patterns lead to the conclusion that neuroandrogenic factors were all but certainly responsible for much of the average sex differences in (a) assertive erotic sexual behavior and (b) status-related aggressive behavior, both in humans in most other mammals. In addition, neuroandrogenic etiology has been demonstrated among several nonhuman species for (c) the acquisition and recall of spatial environmental perception, (d) spacing behavior, (e) pain tolerance and (f) retarded acquisition of aversive conditioning, although for humans, the evidence is only fairly suggestive of neuroandrogenic influence. For six more behavior patterns, most of the evidence was consistent with a neuroandrogenic etiological hypothesis, both in humans and in other mammalian species, but fell far short of justifying definite conclusions. These were (g) diminished fearful emotional responses to threats, (h) task control-oriented tenacity, (i) transient bonding tendencies, (j) peripheralization, (k) sensation seeking and (l) predatory behaviour.