Final answer:
Successful aging is a process of growing old with physical decline but no mental decline, according to Rowe and Kahn and Valliant. It involves maintaining good physical health, high mental and physical functioning, and active engagement with life.
Step-by-step explanation:
The concept of successful aging, according to Rowe and Kahn and Valliant, is a process of growing old with physical decline but no mental decline. In their research, they identified three key components of successful aging: low risk of disease and disability, high mental and physical functioning, and active engagement with life. This concept suggests that aging well involves maintaining good physical health while also staying mentally active and socially connected.