The term personality refers to those relatively enduring aspects of attitudes, feelings, responses, and behaviors that permit us to recognize a particular person whom we have known over time. It is, in a way, a fingerprint of an individual's psychological makeup—the framework of how the individual thinks and acts. Psychiatrists believe that this framework arises out of childhood, powerfully shaped by the actions of parenting and the other social and environmental factors on a complex set of genetic and other biological givens. It is then further molded throughout one's development to achieve more or less lasting form in adolescence and early adulthood.

In the nineteenth century, we said that some people had willpower or a strong character; now we might refer to their good coping skills or to their ego strength—different ways...