In 1950, the psychoanalyst Erik H. Erikson, in a famous treatise on the phases of life development, identified wisdom as a likely, but not inevitable, byproduct of growing older. Wisdom arose, he suggested, during the eighth and final stage of psychosocial development, which he described as “ego integrity versus despair.” If an individual had achieved enough “ego integrity” over the course of a lifetime, then the imminent approach of infirmity and death would be accompanied by the virtue of wisdom. Unfortunately for researchers who followed, Erikson didn’t bother to define wisdom.