Omri Gillath, a social psychology professor at the University of Kansas, said men are likely to pursue short-term mating strategies when faced with a threatening environment.
"We're biologically wired to reproduce, and the environment tells us the best strategy to use to make sure our genes are passed on," Gillath said in a statement.
"If you think you might die soon, there's a huge advantage for a man to use short-term mating strategies -- to make sure there are a bunch of offspring and hope that some of them survive -- but women can't do the same thing."
In the study, Gillath had two groups of men think either about their own death or about dental pain. Then showed them pictures on a computer with sexual images and non-sexual images.
The study, scheduled to be published in the November journal of Experimental Social Psychology, found men responded more vigorously to sexual pictures and had increased heart rates when viewing them, compared with when they thought about dental pain. The two groups exhibited no difference in response times for non-sexual images.
"In low survivability conditions, we think that men would be more apt to pursue sex outside of a monogamous relationship, looking for ways to spread their genes," Gillath said.