<p><b>''A new approach to mental disorder. Randolph Nesse''s insightful book suggests that conditions such as anxiety and depression have a clear evolutionary purpose ... This intriguing book turns some age-old questions about the human condition upside down'' Tim Adams, <i>Observer<br><br></i>One of the world''s most respected psychiatrists provides a much-needed new evolutionary framework for making sense of mental illness</b><br><br>With his classic book <i>Why We Get Sick</i>, Randolph Nesse established the field of evolutionary medicine. Now he returns with a book that transforms our understanding of mental disorders by exploring a fundamentally new question. Instead of asking why certain people suffer from mental illness, Nesse asks why natural selection has left us with fragile minds at all.<br><br>Drawing on revealing stories from his own clinical practice and insights from evolutionary biology, Nesse shows how negative emotions are useful in certain situations, yet can become