In times of adversity, newborn girls are more likely to survive.
The study findings appear in the early online edition of Proceedings of the National Academy of Sciences.
Researchers from Duke University and University of Southern Denmark analysed the mortality data going back roughly around 250 years for people whose lives were cut short by different disasters like starvation or diseases or other misfortunes.
Case studies included the Irish starvation of 1845-1849, the Iceland measles epidemics of 1846 and 1882, and the experiences of freed Liberian slaves returning to Africa from the U.S. in the early 19th century, where they encountered a very different disease climate which killed many.
Dr Virginia Zarulli, assistant professor of epidemiology and lead author of the study, wrote in the journal PNAS: 'Even though the crises reduced the female survival advantage in life expectancy, women still survived better than men.
"The data spanned seven populations in which the life expectancy for one or both sexes was a dismal 20 years or less".More news: First pediatric flu death reported in Ohio
They found that more than 40 per cent of freed American slaves who were relocated to Liberia in West Africa in the 1800s died from tropical diseases during their first year. Babies born during that time rarely made it past their second birthday.
The only exception was in the Trinidadian slave trade, where men outlived women, but the researchers believe that slave traders have a greater incentive to keep male slaves alive, because they were worth more.
However, even when mortality was very high for both sexes, women still lived longer than men by six months to nearly four years on average.
During Sweden's last major starvation, in 1771, abnormal weather resulted in widespread crop failures and life expectancy dropped to 17.15 years for males and 18.79 for females.
Girls born during the starvation that struck Ukraine in 1933, for example, lived to 10.85, and boys to 7.3 - a 50 percent difference.
"Most of the female advantage was due to differences in mortality among infants". Newborn girls are hardier than newborn boys.
And biological differences between the sexes, could also help explain why women are more resilient, the scientists said. The male sex hormone may also harm the immune system.