The activity theory of aging proposes that older adults are happiest when they stay active and maintain social interactions. These activities, especially when meaningful, help the elderly to replace lost life roles after retirement and, therefore, resist the social pressures that limit an older person's world. The theory assumes a positive relationship between activity and life satisfaction. Activity theory reflects the functionalist perspective that the equilibrium, that an individual develops in middle age, should be maintained in later years. The theory predicts that older adults that face role loss will substitute former roles with other alternatives.
The theory was developed by gerontologist, or, scholar of aging, Robert J. Havighurst in 1961, and was originally conceived as a response to the recently published disengagement theory of aging. The disengagement model suggests that it is natural for the elderly to disengage from society as they realize that they are ever nearer to death. However, withdrawing from their central societal roles—working, marriage, raising a family—means they drastically lose social life space and so suffer crisis and demoralization.
Havighurst's activity theory is at deliberate odds with what some perceive as the pessimism of disengagement theory. However, critics of activity theory state that it overlooks inequalities in health and economics that hinders the ability for older people to engage in such activities. Also, some older adults do not desire to engage in new challenges.
Five decades of gerontological research, however, suggest that the activity model is more accurate than the disengagement model . Not only is activity beneficial for the community, but it engages older adults (both physically and mentally) and allows them to socialize with others. This increases feelings of self-worth and pleasure, which are important for happiness and longevity.