How physically and psychologically healthy are Americans at midlife? And why do some experience greater well-being than others? The MacArthur Foundation addressed these questions head-on by funding a landmark study known as Midlife in the U.S. (MIDUS). How Healthy Are We? presents the key findings from the survey in three sections: physical health, quality of life and psychological well-being, and the contexts of midlife. This wide-ranging study measures not only health - the absence of illness - but also reports on the presence of wellness in middle-aged Americans. Researchers, policymakers, and others concerned with the quality of midlife will welcome its insights.