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...

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...

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...

We examine how multitasking affects performance and check whether women are indeed better at multitasking. Subjects in our experiment perform two different tasks according to three treatments: one where they perform the tasks sequentially, one where they are forced to multitask, and one where...

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 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...

We examine how multitasking affects performance and check whether women are indeed better at multitasking. Subjects in our experiment perform two different tasks according to three treatments: one where they perform the tasks sequentially, one where they are forced to multitask, and one where...

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...

Gender differences in competitiveness are often discussed as a potential explanation for gender differences in education and labor market outcomes. We correlate an incentivized measure of competitiveness with an important career choice of secondary school students in the Netherlands. At the age...