About one of every 10 people is left-handed. That can be profitable if you’re a pitcher – and a pain if you’re an average Joe living in a right-handed world. Howard Kushner – a south paw himself – joins us to talk about why so few people are lefties – and about the many ways cultures worldwide discriminate against them. His new book is called “On the Other Hand: Left Hand, Right Brain, Mental Disorder, and History” (Johns Hopkins University Press).