Suppose you’re in a raffle with a chance of winning £100. Before making the draw, the organizers offer you the option of having some or all of your potential winnings go directly to the charity of your choice. Do you donate? And, if so, how much?
You’re probably familiar with the saying that nice guys finish last. But, happily, one recent study suggests that – when it comes to the mating game – this isn’t necessarily true. The participants were given the same choice I gave you, but in a real-life draw, meaning that real money was potentially at stake. Overall, around 58% of men and 70% of women chose to donate.
The participants were also given questionnaires about their sexual and relationship history. Interestingly, participants who were willing to donate some of their potential winnings reported having more sexual partners both overall and in the past year, as well as more casual-sex partners and – for men – more dating partners.
These findings suggest an answer to the long-standing question of why humans are (sometimes) altruistic, even though this may seem to have a disadvantage in evolutionary terms. Generosity is what biologists call a “costly signal” of evolutionary fitness: If you’re so rich that you can afford to give money away, your genes are probably pretty good.