Why have a burger when you have steak at home?

Cheating is one of the most hurtful things a partner can do but it's a fact - burgers are tasty and some people just get a bit fed up of steak. If you don't fancy being the steak in this situation, you're better to go for a partner who's intelligent. That's according to a new study from Finland, anyway, which found intelligence to be an important trait for long-lasting, faithful relationships. Researchers at the Hanken School of Economics looked over military conscription records relating to almost 200,000 Finnish men and found that there was a correlation between intelligence and marital history. The military records contained data from intelligence tests the men took when they joined the army. Following up with the men after five years, the study showed that among the men under 45, the more intelligent they were, the more likely they were to get married and stay married.

"In parallel to the effect of a peacock’s mysterious tail on its mating success… human intelligence has a direct positive impact on human mating prospects in terms of marriage," said lead researcher Jaako Aspara.

But why do smarter men make for longer-lasting marriages? The researchers argued that intelligence and its benefits (including the ability to earn a decent living) makes men more attractive to partners and therefore more likely to marry. Psychology Today's Susan Krauss Whitbourne reckons that intelligence makes a marriage more likely to last as intelligent men might be better communicators.