“In socially monogamous animals, very few individuals end up with the perfect partner because, of course, he or she is likely to be paired to someone else. That is, lots of men would like to be married to, say, Angelina Jolie, and lots of women would love to be married to Brad Pitt. But the reality is that they can’t and only someone like Brad Pitt is able to marry someone like Angelina Jolie,” lead author Simon Griffith told Discovery News.

“So how does a female respond to her real partner?” Griffith, an associate professor in Macquarie University’s Department of Biological Sciences, asked.

“Work over the past few decades has shown that females can actually make a number of subtle strategies to improve their own fitness,” he added, explaining that these include sleeping with other males that could improve the genetic fitness of any potential offspring.