No evidence of effects of testosterone on economic preferences: Results from a large (N =1,000) double-blind randomized controlled study

Abstract

There is conflicting evidence on whether testosterone affects economic preferences such as risk taking, fairness and altruism, with the evidence suggesting significant effects coming from correlational studies or small underpowered testosterone administration studies. To credibly test this hypothesis, we conducted a large pre-registered double-blind randomized controlled trial with N = 1,000 male participants; 10-20 times larger than most previous randomized controlled studies. Participants were randomly allocated to placebo or intranasal testosterone increasing testosterone by 60-80%. They thereafter carried out a series of economic tasks capturing social preferences, competitiveness and risk preferences. We fail to find any evidence of a treatment effect for any of our nine primary outcome measures, thereby failing to replicate several previous studies reporting positive findings that used smaller sample sizes. In line with these results, we furthermore find no evidence of an association between basal testosterone and economic preferences, failing to also replicate previous correlational studies.

Keywords: testosterone, economic preferences, risk taking, hormones