Single-dose testosterone administration impairs rational thinking in men

Gideon Nave
Caltech

The male sex hormone testosterone (T) is released in the body and the brain in response to external 
stimuli, influencing diverse social behaviors context sensitively. We investigated the causal effects of T 
administration on human decision making using a dual-process framework. 244 males received either T 
or placebo under a double blind protocol and took the Cognitive Reflection Test (CRT) that assesses 
one's ability to suppress an intuitive incorrect answer in favor of a deliberative correct answer. T 
administration significantly impaired subject’s CRT performance. The effects were robust to controlling 
for math skills, age, mood and the levels of other measured hormones.