Postponing old age: Evidence for historical change toward a later perceived onset of old age.

"At what age would you describe someone as old?" Perceptions of when old age begins might be prone to upward shifts because of historical increases in life expectancy and in retirement age, as well as because of better psychosocial functioning in later life. We investigated historical changes in within-person trajectories of the perceived onset of old age using data from 14,056 participants who entered the German Ageing Survey at age 40-85 years and who completed up to eight assessments across 25 years. Using longitudinal multilevel regression models, we found that at age 64, the average perceived onset of old age is at about age 75 years.