Why Can't a Woman Be More Like a Man?

Why are there two sexes? How different are they and why? Why can't a woman be more like a man? Or should the question be: why can't a man be more like a woman? Controversy rages around sex and gender, but just what are the differences and how are they determined? Lewis Wolpert, distinguished scientist, broadcaster and author, has tackled depression, religion and old age from a developm...