Researchers who study the influence of hormones on behavior have the greatest difficulty in associating testosterone with any human behaviors whatsoever. They have injected all kinds of animals at all stages of development with synthetic testosterone to see how it affected their behavior. They have juggled the naturally occurring estrogens and androgens to see whether the role of receptors and sensitizers was more important than the action of the hormones themselves. Yet they still can not define any specific influence of testosterone on the behavior of the human male.
Research has long indicated that androgens, testosterone in particular, are linked not only with libido but with aggressiveness, particularly in the male. Animal research has been much more consistent in suggesting this hypothesis than human research has. However, the fact that sexual awakening in the adolescent is associated with rises in testosterone level, does link it to libidinal urges and possibly to aggression.
The testosterone levels of violent men have been measured time and again, and often, but not always, found to be higher than those in a control population. Violent sex offenders have been found, again not consistently, to have the highest testosterone levels of all. The effect of alcohol and drugs is variable; habitual use suppresses testosterone but occasional use can stimulate secretion, possibly as a feed-back effect of disinhibition.
This raises a further possibility that violent men are not violent because they have more testosterone to cope with, but that they have more testosterone because they are more violent. Traditional patterns of male activity might have developed because they stimulate the secretion of testosterone. If a woman can have an estrogen ‘high’, it seems likely that a man can have a testosterone ‘high’.