Aging has many components of change that varies from adult to adult:
Cognitive function changes
Alteration in brain anatomy
Change in neurochemistry
Variance in physiology
Two different components define biological aging:
Internal biological clock
Accumulation of insults to the organism (what damage and external stressors influence the aging adult)
The lifespan can differ with biological aging as well as individual longevity and its relation to specific environmental circumstances and individual differences.
Differences in Influences and Genetics
Influencing an individual’s pathogens and external stressors can alter one’s normal genome which can result in the significant difference between a healthy and cognitively