Women are often less willing than men to compete, even in tasks where there is no gender gap in performance. Also, many people experience competitive contexts as stressful and previous research has documented that men and women sometimes react differently to acute stressors. We use two...

Comparative payment schemes and tournament-style promotion mechanisms are ubiquitous in the work place. We test experimentally whether they have a negative impact on the willingness to cooperate. Participants first perform in a simple task and then participate in a public goods game. The payment...

I analyze Dutch survey data that contains rich information on political preferences, personality traits, and socioeconomic background. I show that voting and political opinions are better predicted by personality and economic preferences than by a rich set of socioeconomic characteristics....

How do people react to setbacks and successes? I introduce a new measure of challenge-seeking to determine the effect of winning and losing in a competition on the willingness to seek further challenges. Participants in a lab experiment compete in two-person tournaments and are then informed of...

We use fluctuations of female sex hormones occurring naturally over the menstrual cycle or induced by hormonal contraceptives to determine the importance of sex hormones in explaining gender differences in competitiveness. Participants in a laboratory experiment solve a simple arithmetics task...

It is now generally accepted that some people are more altruistic, more trusting, or more reciprocal than others, but it is still unclear whether these differences are innate or a consequence of nurture. We analyse the correlation between handedness and social preferences in the lab and find...

We examine whether social preferences are determined by hormones. We do this by investigating whether markers for the strength of prenatal testosterone exposure (finger length ratios) and current exposure to progesterone and oxytocin (the menstrual cycle) are correlated with choices in social...

I study how gender differences in willingness to compete evolve over time in response to experience. Participants in a lab experiment perform the same real-effort task over several rounds. In each round, they have to choose between piece-rate remuneration and a winner-takes-all competition. At...