Does a Dose of Testosterone Make Trusting Women More Skeptical?

All it takes for some people to be a little less trusting of their fellow humans is a little more testosterone, according to a new study in the Proceedings of the National Academy of Sciences. Researchers led by Jack van Honk of the Netherlands used a sample of 24 women in their study. The team showed photos of 150 strangers' faces to the women and asked them to rate the faces for trustworthiness, using a scale from -100 to +100. The scores women gave after receiving a placebo became their "baseline" score. The women also completed a trustworthiness survey after being given an increase in testosterone instead of placebo (they weren't told when they received which).