Final answer:
The disengagement theory of aging suggests that old age is marked by the mutual withdrawal of older persons and society. However, this theory is no longer universally accepted.
Step-by-step explanation:
The theory of aging that suggests old age is marked by the mutual withdrawal of older persons and society is called the disengagement theory. According to this theory, it is natural for older individuals to withdraw from social relationships and society as they age. They receive less reinforcement to conform to social norms, allowing for greater freedom from social pressures. However, it is important to note that this theory is no longer universally accepted and has been criticized for not accounting for the wide variation in the aging process.