I’m a few weeks away from my 80th birthday, which turns out to be a cultural watershed of sorts — the dividing line between being “in your 70s” and “in your 80s’, which is definitely old age. But that doesn’t actually make a lot of sense: the decades according to the calendar correspond to no natural physiological milestones, especially not ones so very sharply delineated. One period of life shades into another, with relatively long transitions.
The matter isn’t just theoretical, but of great practical significance, as detailed at some length in the New York Times on-line on 2/20/20, in “The Upshot: How Common Mental Shortcuts Can Cause Major Physician Errors: Tendencies like left-digit bias can have life-altering consequences for patients” by Anupam B. Jena & Andrew R.Olenski (in the print edition on 2/21, under the title “Are you 79½ or 80? Your Doctor’s View May be Life-Altering”):




