Does a single dose of testosterone increase willingness to compete, confidence, and risk-taking in men? Evidence from two randomised placebo-controlled experiments.

The sex steroid hormone testosterone regulates aggression and display of dominance in non-human animals. According to the Challenge Hypothesis, these effects arise from context-sensitive testosterone increases that facilitate inter-male competitions over resources, status, and mates. A growing body of literature documents similar testosterone effects on behaviors related to competition and risk-taking in humans, though the findings have been mixed.

How people know their risk preference.

People differ in their willingness to take risks. Recent work found that revealed preference tasks (e.g.

On the Relationship between Cognitive Ability and Risk Preference.

Many decisions of individuals involve a combination of internal preferences and mental processes related to cognitive ability. As Frederick (2005) argued in this journal, "there is no good reason for ignoring the possibility that general intelligence or various more specific cognitive abilities are important causal determinants of decision making." Since then, a number of empirical studies have focused on the relationship between cognitive ability and decision-making in different contexts.

No evidence for an effect of testosterone administration on delay discounting in male university students.

Intertemporal choices between a smaller sooner and a larger delayed reward are one of the most important types of decisions humans face in their everyday life. The degree to which individuals discount delayed rewards correlates with impulsiveness. Steep delay discounting has been associated with negative outcomes over a wide range of behaviors such as addiction.

Testosterone administration reduces lying in men.

Lying is a pervasive phenomenon with important social and economic implications. However, despite substantial interest in the prevalence and determinants of lying, little is known about its biological foundations. Here we study a potential hormonal influence, focusing on the steroid hormone testosterone, which has been shown to play an important role in social behavior.