This dissertation tests the efﬁciency of collective sanctions as a preventive measure experimentally with three different cases: (i) collective sanctions and the production of public good; (ii) collective sanctions and intergroup cooperation, and (iii) collective sanctions and peer punishment. The dissertation demonstrates that in all three cases the functionalist hypothesis of a potential efﬁciency of collective sanctions does not ﬁnd empirical support. In the ﬁrst chapter, I test if sanctions applied to an entire group for the free-riding of one of its members can increase the level of cooperation within that group. To measure the efﬁciency of such collective sanctions, I conducted a lab experiment based on a standard public good game. The results show that overall, collective sanctions are inefﬁcient. Moreover, when subjects are able to punish their peers, the level of cooperation is lower in the regime of collective sanctions than under individual sanctions. The second chapter tests whether collective sanctions applied by outgroup members result in higher intergroup cooperation, and whether the introduction of collective sanctions increases the amount of ingroup punishment. The results demonstrate that neither of these two functionalist arguments come true: participants avoid using collective sanctions against outgroups, and the amount of intergroup (third-party) punishment is no higher under the intergroup collective sanctions regime. As a result, the introduction of intergroup collective sanctions does not result in the higher degree of intergroup cooperation. The third chapter analyzes how the introduction of collective sanctions affects the willingness to punish norm violations. I conducted a lab experiment in which participants can choose to take money from a charity. After having taken their own decision, they can observe the decisions of others, and can decide to punish them. The results demonstrated that collective sanctions signiﬁcantly increased the frequency of peer punishment. However, this increased rate of punishment did not go along with lower crime rates.