ScienceDaily : Extra Testosterone Reduces Your Empathy, Researchers Find

A new study from Utrecht and Cambridge Universities has for the first time found that an administration of testosterone under the tongue in volunteers negatively affects a person's ability to 'mind read', an indication of empathy. The findings are published this week in the journal Proceedings of the National Academy of Sciences.

In addition, the effects of testosterone administration are predicted by a fetal marker of prenatal testosterone, the 2D:4D ratio. The study has important implications for the androgen theory of autism (testosterone is an androgen) and confirms earlier rodent research that shows that testosterone in early brain development organizes the activation of the very hormone in later life.
The difference in the way male and female brains work is in most cases purely hormonal. Higher testosterone levels have been linked with increased aggressiveness, sense of competition, spacial abilities, sense of orientation, logical thinking, and now also reduced abilities to recognise emotions and empathise with others.