Does buying your date dinner work? (or, “the second big reason you shouldn’t trust evolutionary psychology”)

It’s often said that “the way to a man’s heart is through his stomach”, but is there any scientific merit to this idea? And what of the reverse? After all, men are often expected to pay for their dates’ meals. Does providing your partner with food improve your chances romantically? In the animal kingdom this is known as “courtship feeding”, yet it seems to be absent from humans.

After all, no known culture openly trades sex for food (outside of prostitution). A hunter brings down a gazelle with a spear on the Savannah and offers a potential partner some meat and she’ll say it doesn’t influence her decision over whether to make hunter-gatherer babies together (or vice versa, after women in these societies tend to provide half of the calories in the diet; if not more than that).

Yet new research by psychologists suggests courtship feeding is still alive and well in humans, we just don’t realise it. They showed more than 200 students videos of couples doing a variety of (completely innocent) things with food. In one scenario there was none present, the two people just talked. In another they were simply eating together. Then they ratcheted up the sauciness (pun completely intended), with one person giving the other some of their food. The final, most scandalous scenario, involved one member of the couple feeding the other.

How "intimate" the dates were rated. "Provisioning" refers to sharing food, feeding is self explanatory

How “intimate” the dates were rated. “Provisioning” refers to sharing food, feeding is self explanatory

When asked to rate how “intimate” the date was and how strong a relationship the two people had with each other, the more food was involved the more highly the date was ranked; despite the fact people say food sharing doesn’t influence their choice in mates. So, perhaps evolution has left us with an appreciation for courtship feeding after all. Right?


This study highlights a very common flaw with a large swathe of evolutionary psychology; and is the second reason you should be skeptical of claims made about evolution influencing our cognition (the first being that such studies tend to rely on un-representative samples, an issue I’ve discussed before). And what is the big problem here? Congruence bias.

This is the fallacy of not indirectly testing your idea. The example wikipedia gives is if you’re shown two buttons and told the left-hand button opens the door. You could press it, vindicating what you were told. You could also test the claim by pressing the right-hand button. The door shouldn’t open, if the experimenter was telling the truth.

This is why it’s very important to have good controls when doing research. But surely, I hear you say, there was a control in this experiment. And you’d be right, they had the people who weren’t eating. But that also means they weren’t really participating in an activity together. If you peel back the facade of food sharing, what this study really says is “talking + an activity is more intimate than just talking.”

To say something meaningful about courtship feeding you need that indirect test to rule out the fact more is going on in the feeding date. Even if you used something really unsexy, like golf, I still reckon you’d see a rise in intimacy rating as the couple did that activity together. You could even have it rise in scandal, like the eating. It starts with just playing golf together. Then one of them starts helping the other. The final stage could be the hands on “teaching them how to swing”.

And then if you got college students to rate these dates I still reckon you’d see a spike in intimacy as they did more stuff together and in closer physical proximity. These are the effects that you need to rule out before you can make any meaningful statements about human evolution and courtship feeding. And a lot of other EvoPsych research also suffers from this flaw, failing to indirectly test the hypothesis to prove your effect really does exist (although it isn’t a flaw limited to evolutionary psychology, other aspects of EvoAnth get it wrong too).

So this research doesn’t really show that your relationship will improve if you feed your partner. Alas, I’m not sure this will convince my girlfriend that I shouldn’t buy her fancy desserts.


Alley, T. R., Brubaker, L. W., & Fox, O. M. (2013). Courtship Feeding in Humans?. Human Nature, 24(4), 430-443.

13 thoughts on “Does buying your date dinner work? (or, “the second big reason you shouldn’t trust evolutionary psychology”)

  1. Not knowing the details, it is hard to judge. Did they control for related nonverbal behavior? Were the couples feeding each other? Touching? Just observing another person eating can be intimate as this seen from “Tom Jones” suggests (after the ad)

    • In all of the instances touching (where not connected to the actions in the experiment) as avoided; along with other signs of affection. Which reinforces the point I was making in the second half of the article: it basically boils down to “people doing something and talking is more intimate than people just talking”. Unless you control for that second variable the results are questionable, but they didn’t. That is congruence bias.

  2. Surely there is no gene that codes a link between receiving food and having sex. It’s impossibly specific. If you needed a gene to specify the association for every adaptive activity pair you have a system prone to failure, and further, unable to adapt.

    The brain is an association machine. Much more reasonable is to want to have sex with people who lower your stress level, who make you feel comfortable, looked after and secure. This could involve all sorts of things including, but not limited too, golf, plumbing repairs, chat, tandem cycling, or a variety of food related activities. Of course, as we all know, the actual performance of these activities could make them a total turnoff, or, turn you into a mouth breather. Especially the plumbing.

    Eating is highly ritualised, possibly using habit and restraint as a way of increasing its level of security, rather than being a war for food.

    The idea of a forced positive association with food brings to mind this witty sequence from Luis Buñuel’s The Phantom of Liberty:

  3. And for this they get grant money? The only person I would presume to feed is the person I have sex with. And yes, like intimate touching, it engenders closeness. And if I saw a couple in a restaurant where one was feeding the other, I would assume they were romantically close, and very likely about to get even closer. But do we gain any insight into animals, or ourselves, or the behaviour, by discussing whether or not this qualifies as “courtship feeding”? I don’t think so.

    • Well if they were correct it could help explain why food and intimacy is linked in our culture. From Lady and the Tramp to the formalities around paying for dates, food and romance is often linked; this could explain why. So I do think it is worthy of research (although maybe not a top priority). Or at least, it would be worthy of research if it was good research.

  4. Or, if you saw a couple in the public library, heads and hands touching, solving a newspaper crossword together, would we label this “courtship problem-solving”, and would we be any the wiser for doing so?

    I do happen to think (though I don’t have the expert knowledge to make the case) that there is such a thing as a valid science of evolutionary psychology. However, it is clearly an area in which it is possible to carry out, and get away with, extremely shoddy research.

  5. Pingback: This week in human evolution (4/8/14): Prehistoric violence in the Middle East, fossils with scoliosis & more | EvoAnth

  6. I can’t speak to “courtship feeding,” and I’m pretty sure there’s no genetic basis, but the learned sensual link between food and sex is extremely strong! Whether it be kissing, nibbling, licking or oral sex itself, our mouths play a significant role in human sexuality.

  7. I definitely feel that eating together helps establish bonds of intimacy, even just with friends. I wish there were more communal meals in life.

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