We study, both theoretically and experimentally, the relationship between the majority threshold chosen by subjects in voting mechanisms and behavioral traits such as their risk attitude and their beliefs on others' political preferences. The main theoretical findings are supported by experimental data. The majority threshold chosen by a subject is positively and significantly correlated with her degree of risk aversion while it is negatively and significantly associated with her confidence on others' political preferences. Moreover, in a treatment in which participants privately observe the distribution of political preferences in a sub-group of participants, we find that the quality of information crowds-out subjective over-confidence.