Although conventional psychology has equated a good grip on reality with mental health, Taylor (Psychology/UCLA) contends that it is normal for people to script their lives with more optimism than their situation warrants and that such ""positive"" illusions are not only benign but beneficial. Relying on the growing body of research that reveals most people to have an inflated estimate of their abilities and a rosy view of the future, Taylor posits the possibility that an optimistic outlook and a sense of control over one's life may be genetically endowed. It has been discovered that infants and small children instinctively believe that they can control the world; that adults with high self-esteem are more motivated to succeed in life; and that these adults also tend to be more creative and more adept at problem-solving. But Taylor finds research that links positive mental attitudes with enhanced physical health to be ""by no means definitive""; still, she devotes an entire chapter to studies that have shown a link. She also differentiates between normal life-enhancing illusions and the delusions of the mentally disturbed; discusses the causes and effects of depression; reveals child-rearing techniques that promote self-esteem and an optimistic outlook--and much more. Solid, wide-ranging research and conclusions.