Lead researcher Maarten Boksem of Rotterdam School of Management, Erasmus University (RSM) in the Netherlands, said that they hypothesized that testosterone could perhaps also lead to prosocial behaviour if such behaviour would be beneficial for maintaining or obtaining social status.
To test this hypothesis, the researchers had 54 female volunteers ingest a liquid solution several hours before participating in an investing game - some volunteers received a placebo solution, while others received a solution with added testosterone.
In the investing game, participants were given 20 Euros and were instructed that they could keep the amount they wanted and invest whatever remained with a trustee (another participant). The invested portion would be tripled and split by the trustee, who would keep whatever portion she wanted and return the rest to the investor.
If participants were completely trusting, they could invest all 20 Euros and hope that the trustee would split the final 60 Euros equally. If they wanted to play it safe, they could keep the 20 Euros for themselves.
Each participant took turns playing both investor and trustee. When they were the trustee, they were always given 60 Euros, indicating that the investor had entrusted them with the task of splitting up the whole sum.
As investors, participants who received testosterone were, on average, stingier - they placed less trust in the trustee and kept more of their initial money. Participants who received the placebo, on the other hand, were more trusting investors, choosing to invest about 3.20 Euros more than those who received testosterone.
Just as they had predicted, testosterone seemed to promote antisocial behaviour in response to a potential threat - in this case, a threat to financial resources.
The new research has been published in Psychological Science.