Thesis: The first chapter of this dissertation presents a theory of child development and parental rearingpractices. In the model, a benevolent parent seeks to transmit cultural norms to her child, whoacquires cognitive skills and develops a capital of appreciation for adopting behaviors that accordwith these norms. Our cultural perspective on the issue of cognitive development provides aninterpretation grid for various results established in the empirical literature. It also permits to identifythe parental characteristics that are conducive to various parenting styles, to child neglect and tochild maltreatment.The second chapter provides a theory of religious prohibition against usury and innovation and itsconsequences on economic activities and occupations. As an economic prohibition from themajority religion is sustained by a threat of social exclusion from that cultural group, it has lesseffects on religious minorities. It then creates an occupational pattern where only the religiousminorities choose activities that transgress the prohibition. By creating resentment against thereligious minorities, this occupational pattern strengthens the diffusion of the majority religion in thepopulation. An economic prohibition is then instigated by the clerics in the majority religion,because it allows them to consolidate their norms and to increase the scope of their control overpopular masses. This work also demonstrates that an economic prohibition lasts longer whenreligious clerics can legitimize secular rulers and when the competition on the religious market isweaker.In the last chapter, we present a microfounded theory of multi-candidate political competition takingan "industrial organization" perspective of politics. The analytical framework is shown to be exibleenough to address several applications on the topics of special interest politics, coalition formationin the legislature in proportional elections, and redistribution under alternative electoral rules