We run an experiment with Danish school children (7-16 years old) to shed new light on gender differences in
competitive behavior. Danish girls are not significantly less likely than boys to choose a competitive scheme
when we control for individual performance, risk preferences, confidence, stereotypes, and interactions with the
opposite gender. However, for the children who perform above average we find a gender gap of 11.8 percentage
points. Our elicitation of the network of friends allows us to study the association between a child’s and their
friends’ competitiveness: for each (extra) friend that is competitive, girls choose to compete more often (+9.6
percentage points). The same is not true for boys. Finally, boys become better at making the correct decision with
age, but girls avoid competition when they should choose it.