She has found that childhood is a critical period for laying down patterns of behavior with biological effects that endure into adulthood. If you want to live a long and healthy life, it helps to have had the right upbringing. Childhood personality traits, assessed in elementary school, predict a person’s lipid levels, blood glucose, and waist size forty years later. These three markers, in turn, predict risk for cardiovascular disease and diabetes. The same childhood traits even predict life span.