There is a large consensus on a significant role of emotions in individual and collaborative settings. In this context, emotion awareness tools (EAT) have been developed to promote the sharing of emotions during computer-mediated collaboration. In this study, we explore whether and how an EAT impacts collaborative processes, and whether there is a gender effect. Results showed that the EAT was beneficial to mutual modeling processes but we found also that men exchanged more verbal acts aiming at improving the relational climate but expressed less divergent opinions with the EAT, which is not the case in women.