This book explores every aspect of the apparent differences between men and women - whether in intellect, emotion, relationships, sexuality or physique - and asks whether biological constraints or culturally imposed stereotypes are responsible for those differences that do exist. The conclusions drawn in the book are based on scientific research and survey material, and this second edition shows updated figures which indicate that there has been progress towards equality in the workplace. He also argues that there is more evidence to strengthen biological explanations of the differences between the sexes.