I am a biological anthropologist who studies primate behavioral ecology. I investigate primate social relationships using both theoretical and empirical approaches. Since 1993, I have conducted research on captive and wild primates, including lemurs, monkeys, and apes. This experience with multiple primate species has given me a broad perspective on primate behavioral ecology that informs my program of research. Generally speaking, my research seeks to better understand the factors that influence primate social relationships. In particular, I focus on (1) power dynamics and sex-biased power structures, and (2) how primates negotiate their relationships within the context group life. My empirical research examines the demographic, ecological, genetic, physiological, morphological, and social influences on primate relationships in wild lemurs. Social relationships are best understood with long-term data. Consequently, I started a long-term study of Verreaux’s sifaka (Propithecus verreauxi) at the Ankoatsifaka Research Station in the Kirindy Mitea National Park in Madagascar.