8Using an evolutionary framework, David C. Geary explains sex differences in parenting, mate choices, competition for mates, social-political preferences, development, brain and cognition, and more. Thoroughly updated and expanded, this third edition includes a chapter on sex differences that emerge in modern contexts, such as differences in occupational choices and variation in sexual orientation, gender identity, and relationships. Scholars from a wide range of sciences have much to learn from this monumental volume.