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 [REF].
His research on mathematical development ranged from mathematical modeling of adults' processing of arithmetic problems;[REF] the effects of aging on these processes;[REF] and cross national and cross generational differences in mathematical abilities [REF].