How are phobias caused? Are they from the thinking mind or the physical brain? Helen Saul demystifies some of our most primal fears in this absorbing guide. Obsessional fears, commonly known as phobias, are as widespread as they are deeply rooted. But what are they and what causes them? Hippocrates thought they were caused by an excess of black bile, medieval theologians blamed evil spirits, and Freud thought they resulted from suppressed sexual desire...