India, Feb. 22 -- In 1800, the average life expectancy in India was 25.4 years; today, it is 70.82 years. Longer life is a global trend, due to substantially better medical intervention and diagnostics. In fact, some believe that in a few years, advanced medical science will ensure that most can expect to live between 100 to 125 years. Perhaps. But scientific data tells us that while life expectancy has, indeed, gone up, maximum life spans have not. The number of centenarians may be doubling every 10 years, but they are still the exception, not the rule.

Why do some people beat the odds, and live up to 100 or beyond? According to the Boston University School of Medicine, genes account for less than one-third of your chances of living bey...