The overarching theme of my research has been to identify situations where male and female reproduction come into conflict with one another. When animals sexually reproduce, one sex generally invests more in the production and care of offspring than another. In mammalian species, this typically is the female due to the high costs of gestation and lactation. Such an imbalance can lead to males and females having conflicting reproductive strategies – a theoretical framework known as sexual conflict. In addition to identifying these situations, I also want to understand how such conflict affects physiology and behavior. Specifically, I examine female counterstrategies to male coercive reproductive tactics, such as infanticide. I tackle this research from an evolutionary perspective while utilizing a comparative (i.e., examining the same research question across different species) and mechanistic (i.e., assessing fecal hormone profiles) approach. My study subjects have been non-human primates (baboons and geladas) living in their natural environments in Africa. These primates provide ideal study subjects because they are highly social animals with a high degree of reproductive skew. In other words, not all animals get to reproduce (the primary currency for evolution), and thus my main line of inquiry is to determine why some animals are more successful at reproduction than others.