Ever wondered why you are so interested in those stale doughnuts in the break room, the mystery-meat-on-a-stick samples at the grocery store, or the less-than-appetising leftovers from that catered work lunch? Despite 25 years working in the culinary industry, I’m still curious. And I’ve seen it all: Customers eating bits of bread meant for testing olive oil; legions of farmers’ market patrons attempting to turn tasters of fruit into a full meal; and double-dippers, dribblers, and “don’t like this, think I’ll put it back” types who have contaminated countless jars of sample jams. No doubt about it, Homo sapiens love free food. The question is, why?

So when Zoe Bain, Refinery29’s food editor, asked if I wanted to write a piece about “why we all go totally bonkers over free food,” my response was a resounding yes. One too many catered lunches at the R29 offices had left Bain puzzled.

“When there’s free food around, we suddenly don’t want our nicely packed lunches anymore,” she said. Even worse, she lamented, “After a catered meeting is finished and the leftovers are opened up to the rest of the office, it turns into a competition of who can get their hands on the freebies first. Everyone gets nervous that if they’re not standing right there, nothing will be left.”

One of the things I find curious about freeloading behaviour is our tendency to eat things that we’d never consume if they weren't free. Anyone who’s ever done a few laps around Whole Foods or Costco just for the samples knows what I’m talking about. To get to the bottom of this age-old phenomenon, I reached out to a number of psychologists and anthropologists who specialise in food-related research. My first question: Could there be an evolutionary explanation?

“In general, I’d be very careful about assigning an evolutionary value to something like the desire for free food,” says Dr. Richard Wilk, professor of anthropology and co-director of the Indiana University Food Institute. “Through two or three million years of human evolution, all food was free. The only differences were in how much time, effort, or danger were involved in getting that food. Almost every human culture studied by anthropologists has an elaborate set of rules about how food is divided, which means that people never grab food, but instead set about sharing it.”

While I think the mother of my ex-boyfriend would disagree with Wilk — the youngest of five siblings, she’s fond of saying if you didn’t eat fast in her house, you didn’t eat at all — his sentiments are echoed by Dr. Amy K. McLennan, a research associate at the University of Oxford.

“In some instances — if governments are giving away ‘free’ food, to, say, starving populations, then the food might instead be treated with suspicion or disdain,” she notes. “But in some societies, sharing food forms a bond between giver and receiver. For example, in the Pacific island nation of Nauru, in pre-colonial times, one way to cope with extended food shortage was to keep preserved fruit in the home. The reason people wouldn’t loot it was because of the social norms and customs that governed keeping, sharing, and distributing food over time. In the same society today, with a more dominant food-anytime-and-everywhere culture, people have to work hard to keep their food hidden, so it’s not taken. If we live in a culture that values getting things at no cost, then you can expect people to go for free samples of pretty much anything.”

Economics may also play a role in our metaphorical hunger for free food. Says Dr. Susan D. Blum, professor of anthropology at the University of Notre Dame, “I think it has to do with the way the idea of ‘free’ has been socialised and the notions of capitalism that give value to something that’s otherwise assigned a monetary cost. In the U.S., we’ve divorced hunger from consumption and there are many other factors affecting appetite.” For anyone who’s ever worked in a restaurant, those words ring all too true. It’s hard to pass up what’s right in front of you, especially when it’s food you couldn’t afford on your own dime.

But maybe the simplest explanation is that we all love getting something for nothing, no matter what our socioeconomic class. It’s possible we also like the feeling of getting away with something.

Explains Dr. Merry White, a professor of anthropology at Boston University, “Food came ‘free’ from the mother’s breast and within the family; most middle- and upper-class children aren’t considering much where their food comes from — it’s mostly ‘free.’ So getting ‘food for free’ has a visceral memory. But then there are twisted, sneaky adult feelings that come into play. Food on airplanes? It used to be ‘free’ and now if you get a bag of pretzels. You’re inordinately grateful: free food!”

That gratitude, while not applicable to unmanned samples found at the grocery store, is key when it comes to trying freebies proffered by farmers’ market or other vendors (speaking from years of experience). Selling direct-to-consumer is the ideal for farmers and food artisans. It’s important to meet the people who grow and raise our food as well as the people who consume it.

As Dr. White points out, “As humans, we’re also looking for relationships, connections, and as an anthropologist, I consider sociocultural factors...in Japanese depachika (department store food halls), there are many stalls with samples. But there’s a code: you don’t just graze, you ask questions, get engaged with the maker. Food for free shouldn’t be anonymous.”

So the next time you’re tempted to race your officemates to what’s left of the morning meeting’s breakfast buffet or nab more than your share of potato chips from the sample bowl at the store, don’t feel bad — it’s human nature.