Testosterone makes women distrustful

14th June 2o10

Is there science behind the cliché that women are naïve and can be easily exploited while men are more cautious and wary? It seems our physiology or lack thereof might be to blame, in particular lack of the sex hormone, testosterone, which is principally a male sex hormone. In a study published in the Proceedings of National Academy of Science last month, scientists found trusting women became more suspicious when given a dose of testosterone.

The researchers at the University of Cape Town, South Africa and Utrecht University, the Netherlands conducted a behaviour experiment with 24 females with the average age of 20. The researchers first separated the groups into “high trusting” and “low trusting” groups by showing the women a series of 150 photographs and asking the women to rate on a scale of -100 (least trust worthy) to 100 (most trustworthy).

Then over a course of three days the subjects received either the placebo (which had no active ingredient) in one round and the testosterone in the other round. Both the participants and the people administering the research did not know what the subjects were receiving, this is called double blinded. They found that women in the “high trust group” after receiving testosterone rated faces 10 points lower than what they had initially indicated. This was found even after accounting for women’s natural levels of testosterone and mood on the day.


Oxytocin is a “feel-good hormone” and has role in social bonding and the warm fuzzy love feeling. The researchers suggest that somehow testosterone counteracts the effects of oxytocin as well as increases vasopressin, a hormone that has been associated with aggression. The authors of the paper (Bos, Terburg and Honk) suggest that “testosterone adaptively increases social vigilance in these trusting individuals to better prepare them for competition over status and valued resources.“ And no surprises there, that they cite other research that shows “testosterone levels in humans correlate positively with financial gain on the stock market and, as such, appear predictive of economic shrewdness.” And to put the nail in coffin, men have ten times more testosterone than females…. I rest my case.

5 thoughts on “Testosterone makes women distrustful

  1. Pingback: Lower Testosterone – How to Avoid It

  2. And how can we not trust a study where one of the authors has the deadly serious name of ‘Jack van Honk’?

  3. Interesting post Muza. That might help me identify a potential predator and get away quicker if possible (or thump his lights out, which is more likely) and that is a great thing but on the sociological level, it’s sad that testosterone is sometimes used as a swear word that diminishes the identity/status of women. I don’t have a hairy chest or a deep voice to attest to higher levels of testosterone but have (according to friends, well-meaning aunts in the village and random victims of my exacting standards) been told often that I behave very much “like a man” in terms of my aggression in getting things done. “Easy on the testosterone” is something I’ve heard not a few times from several doctor friends (not always 100% jokingly!). So my most positive attribute, i.e. efficiency/ productivity, is not credited to me but, to add insult to injury, is seen as a good thing in my male counterparts.

    • But that go get it done and get it done right attitude extends far beyond the work place…..we strive at work and love family and life in equal and bountiful measures…..a wonderfully unique combination that can only be found in phenomenal women!

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