The nurture assumption

In this influential psychology book, Judith Rich Harris questions the common belief that parents are the main force shaping who children become.

Drawing on research from child development and related fields, she argues that peer groups play a far larger role in socialization and personality development than family upbringing alone.

The book was a finalist for the 1999 Pulitzer Prize for General Nonfiction and was originally published in 1998, with a revised and updated edition released in 2009.