Disengagement theory, is the process of individuals withdrawing and isolating from prior social interactions due to age. The disengagement theory of aging states that "aging is an inevitable, mutual withdrawal or disengagement, resulting in decreased interaction between the aging person and others in the social system he belongs to". The theory claims that it is natural and acceptable for older adults to withdraw from society. There are multiple variations in disengagement theory, such as moral disengagement. Disengagement theory was formulated by Cumming and Henry in 1961 in the book Growing Old and was the first theory of aging that social scientists developed. Thus, the theory has historical significance in gerontology. Since then, it has faced strong criticism since the theory was proposed as innate, universal, and unidirectional. The disengagement theory is one of three major psychosocial theories which describe how people develop in old age.