Potentially worrying news for the human race. If future generations are bred from those we want to sleep with, do-gooders are dying out. No one – no matter how depraved – wants to rip the socks and Birkenstocks off anyone.

Yes, if you want us to be brutal we’ll confess – when it comes to sex – we’d rather pull the balaclava off an actual mugger than the bib and clipboard off a chugger. And, worse and worse still, the boffins are on to us – exposing this weird, terrible (and, until now, mercifully secret) perversion. A team of researchers at Yale and Oxford has shown that while we admire people who spend their time helping impoverished communities and donating money for malaria-combating mosquito nets, we’re not keen on shagging them. In fact, we don’t even want to be friends with them. As human beings, we prefer those who concentrate their time and energy on friends and family rather than complete unknowns in dire predicaments.

“When helping strangers conflicts with helping family and kin, people prefer those who show favouritism, even if that results in doing less good overall,” explains Molly Crockett, who authored the study published in the Journal of Experimental Social Psychology. Participants were asked to choose between two “equally moral” scenarios and overwhelmingly preferred those who – for instance – would choose to spend the day with their “lonely mother” over “building homes for Habitat for Humanity”.

As an ex-dating columnist, I was already aware of such bias. It’s even evident on Tinder. Dick pics are posted and no one bats an eyelid. But just try uploading a picture of yourself “do-gooding” on a “gap yah”. Some cruel soul is likely to screengrab and share it with the “Humanitarians of Tinder” Tumblr page. In app-land, all mockery is reserved for the well-meaning.

Of course, one could argue there’s not just psychology but sound sense behind our distrust of those who are so intent on doing good for others. After all, how are they to know what is best for people they don’t know?

In Strangers Drowning: Voyages to the Brink of Moral Extremity, the New Yorker writer Larissa MacFarquhar explores why we are so sceptical of “do-gooders” and why their good deeds make us so uncomfortable. She cites the remarkable tale of two parents who founded a leprosy colony in India and chose to live there – in huts with no walls – even though their two small children might have caught the disease or been “eaten by panthers”.

She points to the Austrian social critic Ivan Illich, who made a speech to young Americans wanting to help out Mexico in 1968. “If you insist on working with the poor,” he said, “At least work among the poor who can tell you to go to hell. It is incredibly unfair for you to impose yourselves on a village where you are so linguistically deaf and dumb that you don’t even understand what you are doing or what people think of you.”

But back to the sex. Do-gooding is all well and good. But unfortunately, when it comes to making babies and hence the future of humanity, we all prefer someone who can – quite simply – do us. So if your notion of “talking dirty” consists of a blow-by-blow account of constructing a mud hut from the brown banks of the Zambezi. Just stop. You’re doing it all wrong.

• Emily Hill is a journalist, and the author of Bad Romance



• This article was amended on 27 August 2018 to remove a reference to mosquito net research.