My research interests include evolutionary and cross-cultural approaches to understanding health and human sexual diversity, especially how variations in gender, sex, and sexual orientation impact psychological wellness and relationships.
I am also interested in the "Big Five" model of personality traits, risk factors for HIV/AIDS, and predictors of both sexual aggression and intimate partner violence across cultures.
I am Founding Director of the International Sexuality Description Project (Schmitt et al., 2003), a cross-cultural survey that included samples from 56 nations representing six continents, 13 islands, and 28 languages. A second wave of the ISDP, the ISDP-2, included more than 200 collaborators and 58 nations.