midlife crisis

Theories of Aging

A(Theories of Aging)-->B(Programmed Theories)-->D(Programmed Longevity)
A-->C(Error Theories)-->M(Wear and Tear)

Why Would Aging Be Programmed into Our Genes?

Factor of evolution; need to procreate

Genetic Preprogramming Theory of Aging

Telomere length reduces every time a cell divides Telomere length = good marker of biological age

built in time limit for reproduction of cells

our longevity is primarily determined at the moment of conception and is largely reliant on our parents and their genes

Wear and Tear Theory of Aging / Deterioration Theory / Fundamental Limitation Theory

aging is caused by progressive damage to cells and body systems with time and use, mechanical functions decline

Disengagement Theory of Aging

Activity Theory of Aging

Jin K. (2010). Modern Biological Theories of Aging. Aging and disease, 1(2), 72–74.