This chapter suggests that plasticity decreases from childhood through old age while flexibility increases from childhood into middle adulthood. It discusses understanding the balance of losses, continuities, and gains in the aging mind. Although short-term memory, reaction time, and basic information-processing and problem-solving abilities appear to decline with normal aging, other cognitive functions seem to remain stable or even improve. Psychologist Erik Erikson made important contributions to our understanding of the aging mind through his theory of ego psychology and individual identity over the course of life. One way of thinking about the continuity of the aging mind comes from stage theories of human development, including ideas of depth psychology from Sigmund Freud, Carl Jung and Erik Erikson. There has been new attention on training and practice in problem-solving skills, memory techniques, and lifelong learning: all strategies that can help compensate for losses and build on the gains of the aging mind.