Prejudice and truth about the effect of testosterone on human bargaining behaviour. (2010)

“…testosterone in women increased fair bargaining behaviour, reducing conflicts and increasing social efficiency. However, subjects who believed they’d received testosterone – regardless of whether they actually did – behaved much more unfairly than those who thought they’d received a placebo.

Christopher Eisenegger (1), Michael Naef (1,2), R. Snozzi (1), M. Heinrichs (3) & Ernst Fehr (1).
1: University of Zurich, 2: University of London, 3: University of Freiburg, Germany
Published in Nature, 463(7279), 356-359

From the abstract:

Biosociological and psychological models as well as animal research suggest that testosterone has a key role in social interactions. Evidence from animal studies in rodents shows that testosterone causes aggressive behaviour towards conspecifics. Folk wisdom generalizes and adapts these findings to humans, suggesting that testosterone induces antisocial, egoistic, or even aggressive human behaviours.

However, many researchers have questioned this folk hypothesis, arguing that testosterone is primarily involved in status-related behaviours in challenging social interactions, but causal evidence that discriminates between these views is sparse.

Here we show that the administration of a single dose of testosterone in women causes a substantial increase in fair bargaining behaviour, thereby reducing bargaining conflicts and increasing the efficiency of social interactions.

However, subjects who believed that they received testosterone – regardless of whether they actually received it or not – behaved much more unfairly than those who believed that they were treated with placebo.

Thus, the folk hypothesis seems to generate a strong negative association between subjects’ beliefs and the fairness of their offers, even though testosterone administration actually causes a substantial increase in the frequency of fair bargaining offers in our experiment.

Access the full paper here: Prejudice and truth about the effect of testosterone