Definition of Age and Aging

By: Jacqueline Böhr MS

“The structure and efficiency of an organ are determined by genetic
and the quality and quantity of the demands made upon it” — Hollmann / Hettinger 2000


Calendar / Chronological Age = numerical scale, whereby individuals are classified based on their date of birth (Meusel/Hubert/Schilling 1980, 15).

Biological / Individual Age = The age an organism presents based on the biological state of its tissue in relation to the standard.  This depends on biological maturing processes and exogenous influences. (Röthig 1983, 21).

One’s calendar age often does not correspond to one’s biological age!

There is also one’s psychological, social , and functional age to consider (which is, however, related to individual age).