Men are known to have a higher taste for competition than women. This paper presents an experiment that analyses the different determinants of the choice to enter a competition : beliefs and the competition level. As far as entry in the competition is concerned, low-performing subjects adapt their decision entry to the level of the competition, whereas high-performers do no. However, the behaviors leading to these results are quite different for men and women : women mainly react to the information on their own performance while men seem to respond more to their beliefs concerning the level of the competition they will be evolving in. Finally, both men and women deviate from their bayesian beliefs and become too pessimistic (optimistic) after a negative (positive) feedback.