From JULIA KOCICH
Charles Arthur states in ‘Design for the third age’ (13 June) that:
‘Until the beginning of this century the average life expectancy was 40;
designers could assume that their users were young.’ This helps to perpetuate
a widespread, careless use of ‘average (mean) life expectancy’.
The statistical mean life expectancy at birth is quite different from
a single individual’s chances of attaining old age. To quote from Aristotle
to Zoos: A Philosophical Dictionary of Biology by the late, great Peter
Medawar and Jean Medawar, ‘In demography . . . a certain fastidiousness
is called for in the use of technical terms . . . The mean expectancy of
life at birth, often used as a measure of the wellbeing and general medical
prowess of a population, has increased dramatically over the past few hundred
years. This is true mainly because of the diminution of mortality in infancy
and childhood . . . The mean expectation of life at later ages has not increased
nearly so much.’
Julia Kocich Astoria, New York
