Working hard to find mate shortens life

BOSTON, Aug. 11 (UPI) -- Finding a mate can be hard work and it may shorten the lives of those who work hard at it, U.S. researchers suggest.

Senior author Nicholas Christakis -- a professor of medicine and medical sociology at Harvard Medical School and professor of sociology at Harvard University -- says the study shows the ratio of men to women affects how hard it is to find a mate and that extra effort can affect longevity.

The study, published in the journal Demography, finds men who reach sexual maturity where they far outnumber women, live, on average, three months less than men whose competition for a mate isn't as tough.

In other words, the steeper the gender ratio, the sharper the decline in lifespan.

"At first blush, one-quarter of a year may not seem like much, but it is comparable to the effects of, say, taking a daily aspirin, or engaging in moderate exercise," Christakis says in a statement. "A 65-year-old man is typically expected to live another 15.4 years. Removing three months from this block of time is significant."