Women Exposed to Testosterone Become Less Trusting

Scientists have recently demonstrated that exposing women to doses of the masculine hormone testosterone makes them less trusting in others, and also more skeptical when it comes to accepting new data. The researchers behind the investigation said that, in their experiments, women who were given the chemical tended to rate images of people's faces as being less trustworthy than women who were only given a placebo. The data supports the conclusion that the hormone does have a direct effect on how men and women perceive others in terms of trust, LiveScience reports.

The science team also reveals that the chemical appears to have had no effect on those women who were qualified from the get-go as being skeptical and untrusting. The results would also seem to suggest that testosterone may have effects opposite to those of oxytocin, the hormone that is known to play an important part in facilitating social bonding in our species. The chemical is also produced in high quantities when we learn to trust other people, and, in men, testosterone may help keep them on their toes, aware of potential dangers from '”bogus” friends. In women, the evolutionary necessity to develop this trait may have never existed.

“To be more successful in competition you have to be sharp […] you have to be also socially sharp. And to be socially sharp it's not smart to trust people you don't know,” explains University of Cape Town scientist Jack van Honk. Keeping this in mind, the experts say that testosterone may therefore be contributing not to aggression directly, but rather to men's desire to climb the social ladder, become more dominant in their groups, and also obtain a higher rank in the social hierarchy. The chemical may also boost vigilance, by making males less trusting, and therefore more watchful to those around them.

The South African team conducted its experiments on a group of 24 women (average age 20), who were given either a placebo, or a dose of testosterone, each. There were two rounds of testing featured in this approach. In the end, all of the women received the hormone, except that those who did not get it the first time received it in the end, but three days later. Each participant was presented with 150 pictures of unfamiliar faces, and asked to rate them. The same women rated the same faces differently throughout the study, depending if they were on testosterone or not, the researchers say.