UCLA

How do social norms spread in a population? Which processes affect whether a social norm persists over time or disappears quickly? These are the questions that guide this dissertation. In modeling the spread and maintenance of social norms, I employ and integrate two theoretical frameworks: cultural evolution theory, an anthropological framework that aims to model how culture changes over time and space and understands cultural change as somewhat analogous to Darwinian evolution; and sexual conflict theory, a theoretical perspective that investigates how conflicts of interests between the sexes play out over evolutionary time. Descriptive social norms refer to common behaviors or conventions of a group. On the other hand, prescriptive social norms say something about what is morally right and how people should behave. I argue that this distinction is crucial for pinpointing the processes affecting the dynamics of social norms, as descriptive and prescriptive norms are likely subject to some shared as well as distinct selective pressures and processes of change. Throughout this work, I use Bayesian statistical inference to empirically test hypotheses on norm change. In chapter 1, I apply the framework of cultural evolution theory to examine how descriptive norms regarding perinatal care as promoted by the Red Cross spread among women in the Kunene region of Namibia. My analyses show that an observed shift towards medical recommendations regarding hospital birth and use of contraceptives is in line with predictions of conformity-biased social learning. In chapter 2, I employ sexual conflict theory to test whether women’s attitudes towards patriarchal gender norms in four East Asian populations reflect their anticipated fitness costs and benefits. I find that part of the variation in women’s attitudes towards gender norms may be explained through their varying interests in these prescriptive norms depending on their age and marital status. I further discuss how women’s social status may be protective against the costs of contesting culturally dominant norms. Lastly, in chapter 3 I propose an integration of cultural evolution and sexual conflict theory that I argue is crucial to understanding the complex relationship between gender norms and sexual conflict in humans.