Psychologists know best, of course, and in the 1950s they warned parents about the dangers of too much love. Besides, what was "love" anyway? Just a convenient name for children seeking food and adults seeking sex. It took an outsider scientist to challenge it. When Harry Harlow began his experiments on mother love he was more than just an outside the mainstream, though. He was a deeply unhappy man who knew in his gut the truth about what love --...