Geary's wide-ranging interests are reflected in invited addresses in a variety of departments (
anthropology, biology,
behavior genetics, computer science, education, government, mathematics, neuroscience, physics, and psychology) and Universities throughout the United States, as well as in Canada, Europe, and East Asia. Geary's research on mathematics learning, evolutionary psychology, and sex differences has been featured in many popular press outlets, including
Discover,
Education Week,
Forbes,
CBS News, and
MSNBC among many others. Geary's research on children's mathematical development resulted in a MERIT award from the National Institutes of Health (NIH). In 2005, the University of Missouri awarded Geary a Curators’ Professorship, and the Thomas Jefferson Professorship in 2009. Among other distinctions, he is 2009 co-recipient of the George A. Miller Award for an Outstanding Recent Article on General Psychology for the 2007 Psychological Science in the Public Interest monograph on sex differences in mathematics and science, co-authored with
Halpern,
Benbow, Gur, Hyde, and
Gernsbacher. He is a fellow of the
Association for Psychological Science (2005) and the
American Association for the Advancement of Science (2011). Geary's research interests are centered on his four books, ''Children's mathematical development (1994), Male, female (1998, 2010, second edition), Origin of mind (2005),
and Evolution of vulnerability (2015)
; the latter was discussed in an interview with the Guardian. He is also co-author of the 2008 Sex differences: Summarizing more than a century of scientific research,'' and co-editor with Drs. Berch and Mann Koepke of a five-volume series on mathematical cognition and learning. His research on mathematical development ranged from mathematical modeling of adults’ processing of arithmetic problems; the effects of aging on these processes; and cross national and cross generational differences in mathematical abilities. In this area, he is best known for his research on learning difficulties in mathematics and in 1993 published a theoretical and review article that outlined subtypes of disabilities and helped to organize subsequent research in this area. He currently directs the Missouri Longitudinal Study of Mathematical Learning and Disability. Geary's research in evolutionary psychology also ranges across a variety of issues, from evolution of the hominid brain to men's hormonal responses while competing against members of their in-group or against an out-group. He has also written extensively on human paternal investment (fatherhood) and the evolution of the human family, and is one of the pioneers in evolutionary developmental psychology and
evolutionary educational psychology. His collaborators include former students, Drew H. Bailey and Benjamin Winegard with research focused in social signaling, among other topics. ==Public service==