Childhood, adolescence, even the "twilight years" have been extensively researched and documented. But the vast terrain known as midlife—the longest segment of the life course—has remained uncharted. 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.," or MIDUS. For the first time in a single study, researchers were able to integrate epidemiological, sociological, and psychological assessments, as well as innovative new measures to evaluate how work and family life influence each other.

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 (family, work) of the midlife. The topics covered by almost forty scholars in a wide variety of fields are vast, including everything from how health and well-being vary with socioeconomic standing, gender, race, or region of the country to how middle-aged people differ from younger or older adults in their emotional experience and quality of life. This health—the study measures not only health-the absence of illness—but also reports on the presence of wellness in middle-aged Americans.

The culmination of a decade and a half of research by leading scholars, How Healthy Are We? will dramatically alter the way we think about health in middle age and the factors that influence it. Researchers, policymakers, and others concerned about the quality of midlife in contemporary America will welcome its insights.

* Having a good life means having good relationships with others to almost 70% of those surveyed. Less than 40% mentioned their careers.

* Reports of disruptive daily stressors vary by age, with young adults and those in midlife experiencing more than those in later adulthood.

* Men have higher assessments of their physical and mental health than woman until the age of 60.