46% of pre-retirees do not believe that they will live as long as the average population, according to a July report from the Society of Actuaries. Underestimating their life expectancy is another reason they're likely to exhaust all their resources, other than Social Security, in the early years of retirement.
(USA Today, today, in article: Test-drive retirement before taking it on the road)
Really, 46% don't think they'll live as long as average? There may be some weird psychosocial implications of that, but statistically speaking, it sounds as though Baby Boomers at least paid attention in math class.