section_path: Definitions/Dimensions
section_name: Dimensions
paragraph_text: Dimensions
  
  Key Concepts in Social Gerontology lists four dimensions: chronological, biological, psychological, and social. Wattis and Curran add a fifth dimension: developmental. Chronological age may differ considerably from a person's functional age. The distinguishing marks of old age normally occur in all five senses at different times and at different rates for different people. In addition to chronological age, people can be considered old because of the other dimensions of old age. For example, people may be considered old when they become grandparents or when they begin to do less or different work in retirement.