Does perception of life expectancy reflect health knowledge?

Analysis of original survey data shows White male smokers estimate their longevity as four years less than that of nonsmokers, roughly the actuarial difference. Those who do not exercise perceive the same life expectancy as those who exercise, somewhat inconsistent with available information on mortality. Men with long-lived parents and grandparents expect to live 12-18 years longer than those with short-lived forebears, far longer than studies of actual longevity imply. Men who are more than 15 per cent overweight expect to live four years less, a larger impact than the published actuarial difference.