Sexual scientists have long believed that testosterone plays an important role in generating sexual desire. Just consult any Human Sexuality textbook and you’ll likely find a lengthy section talking about this hormone’s role in producing both male and female sexual interest and arousal. However, recent research is challenging some of our most widely held beliefs in this area. In particular, the idea that there is a positive, linear association between testosterone and desire (i.e., that increases in testosterone necessarily correspond to increases in desire) does not seem to hold up. In addition, this hormone may have somewhat different sexual effects in men and women.
As some evidence of this, a recent study examined how testosterone is related to desire for both solo and partnered sexual activity in young, healthy men and women whose hormone levels were within the normal range . Participants were 196 college students and community volunteers (91 women and 105 men) who completed a battery of questionnaires about their sex lives and submitted saliva samples that could be tested for hormone levels. The major findings were as follows:
-Women who expressed more desire to masturbate had higher levels of testosterone than women who had no desire to touch themselves. However, women’s desire for partnered sex was not related to testosterone in the same way, and the association actually depended upon whether women were under stress (which was determined by the amount of the stress hormone cortisol present in their saliva). For women who were low in stress (i.e., women who had lower levels of cortisol), there was no association between testosterone and desire for partnered sex. For women who were high in stress (i.e., women who had higher levels of cortisol), testosterone was actually associated with less desire for partnered sex. Thus, among women, high testosterone was linked to more desire to masturbate, but not more desire for partnered sex.
-Surprisingly, among men, there was no association at all between testosterone levels and their desire for masturbation or partnered sexual activity.
-Consistent with past research, men reported more desire for both masturbation and partnered sex than did women. Men also had higher levels of testosterone. However, differences in this hormone did not statistically account for the sex differences in desire. Thus, testosterone differences did not explain why men had more desire than women—there seems to be something else going on here, perhaps something social or psychological in nature (e.g., maybe women weren't accurately reporting their sexual desire due to social pressures).
These findings tell us a few important things. First, the association between testosterone and desire may not be as simple and direct as many of us have been led to believe. In fact, the only case where higher testosterone was even linked to increased sexual desire was when considering women’s interest in masturbation. This particular finding also tells us that testosterone is not necessarily related to sexual desire in the same way in men and women (e.g., perhaps desire to masturbate is driven more by hormones in women, but is triggered by other factors in men) . Lastly, testosterone does not seem to explain differences in male and female sexual desire, which runs contrary to what many scientists have assumed for years.
These results should not be taken to mean that testosterone is unimportant when it comes to sexual desire, because it certainly still is. For instance, there is a very large body of evidence indicating that extremely low levels of this hormone (due to genetic conditions, castration, aging, etc.) typically diminish sexual desire. It is important to keep in mind that this study only considered people whose hormone levels were in the normal range—thus, they do not reflect what happens at unusually high or low levels of testosterone. These new findings simply tell us that (1) when you reach a certain minimum level of testosterone, further increases up to a certain point do not always change behavior in the way that you might expect and (2) for a complete understanding of what drives sexual desire, we must take into account biological, psychological, and social influences.
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 van Anders, S. M. (in press). Testosterone and sexual desire in healthy men and women. Archives of Sexual Behavior.
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