In a non-judgmental book that should prove comforting to men and women struggling through the ""second identity crisis,"" the Davitzes write about the pitfalls involved in creeping through the decade after Youth has officially ended. For either sex, a 40th birthday can be a trauma. Suddenly a man recognizes his mortality, and the ramifications of that often take him on a ten-year binge of discontent with everything that had always pleased him, including his wife. Women, plagued by hormonal (and consequently emotional) swings of their own, find their children grown and gone, their husbands irritable strangers, and their male colleagues passing them by for promotion. When successes come, the authors say, they come too late to yield real satisfaction. But as fifty approaches, things automatically settle down. Though the Davitzes offer no real solutions, they do provide a magnum of empathy.