There’s a reason bleu cheese, olives, and wasabi don’t appear on kids' menus: All three ingredients have assertive flavors that would turn off most children with functioning taste receptors. But something interesting happens after several years of development—many of the same kids that used to gag at anything bitter or funky start to accept, or actively seek out, those same bold flavors in their diets. This change has nothing to do with maturing taste buds. Rather, it can be explained by the purely psychological phenomenon of acquired taste.

Paul Rozin, a professor of psychology at the University of Pennsylvania, defines acquired taste as any taste that humans aren’t predisposed to like. "You're starting out with a little library of innate preferences and aversions," he tells Mental Floss. "So most of the rest of what you have are acquired likes and dislikes."

Humans are born liking sweet foods and drinks, and they show an innate aversion to heat, bitterness, and other strong flavors. In other words, acquired taste isn’t limited to durian, liver, anchovies, and other foods that are polarizing among adults. Any food preference that doesn’t appeal to our most basic, ingrained desires has been acquired. That means broccoli, hot sauce, beer, pickles, ginger, dark chocolate, miso, and yogurt are all acquired tastes.

How Tastes Get Acquired

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People can acquire tastes at any age, and not much research has been done into when these preferences tend to evolve. Anecdotally, at least, adolescence seems to be a critical time. At this point in life, people are very susceptible to peer influence, which may be one of the biggest factors driving acquired taste. “If people you like like a flavor, that tends to make you like it,” Rozin says. “If your peers do it, that's very important. If heroes like Hollywood people do it, it tends to make you like it. Not always, but it tends to.” So if you grew up watching your older brother eating hot wings, or Anthony Bourdain eating offal, that could explain why you enjoy those foods as an adult.

But most people don’t suddenly fall in love with a food after seeing it on the plate of someone they admire. Usually, acquiring a new taste is a gradual process that’s shaped by numerous variables. One is mere exposure. If someone is exposed to something repeatedly—whether it’s a food, a song, a place, or a group of people—they may start to like it simply because it’s familiar. Mere exposure can explain the vast variation in food preferences across cultures. Spicy dishes are everyday fare in certain Asian, African, and Latin American countries, but those same foods may be inedible to someone from Scandinavia. Hot peppers contain capsaicin, an irritant that creates a burning sensation on the tongue. To someone who’s never tried a hot pepper (or hasn’t tried a lot of them), this feeling would be naturally unpleasant, but people who grew up eating peppers have had their whole lives to get used to the heat.

This doesn’t just apply to foods that cause physical discomfort. In some European countries, aged cheeses like limburger, stilton, and camembert are popular parts of the cuisine. Many people in East Asia would be disgusted by what’s basically rotten dairy, but they’ll happily eat decayed fish in the form of fermented shrimp paste or fish sauce. In both cultures, the innate aversion to decay is still present, but they’ve made special exceptions for the flavor through mere exposure.

Acquired Taste: An Ancient Survival Mechanism

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So how can some people grow to love funkiness in their cheese but not in their seafood? There’s a third factor that determines if someone will grow to love a taste, and that’s conditioning. Acquired tastes like spicy, bitter, and sour are rarely the sole component of a dish. They’re typically paired with flavors humans are more inclined to like, such as sweet and fatty. (People don’t exactly “taste” fat, but the brain does perceive it). After drinking enough Frappuccinos, one might link the bitter flavor of coffee with cream and sugar. If they were to switch to black coffee, their brain might produce the same pleasure response it associates with the sweeter version of the drink. The same goes for cheese and fish sauce: Even the most pungent cheese is still salty and fatty, and fish sauce is used as a flavoring in dishes with other delicious ingredients like noodles, sugar, and meat. In those cases, it isn’t just the funky flavor people are seeking out, but the associations it has with other, more palatable tastes.

Acquired tastes are part of practically every culture’s cuisine and some of the world’s most beloved dishes. Without expanding beyond innate preferences in their diet, humans wouldn’t be able to get the nutrients they need to survive. But there’s a good reason people aren’t born with a taste for bitter vegetables and fermented foods. Without knowing any better, seeking out these flavors could be deadly.

Humans have an innate aversion to decay because that odor and flavor signals that a food has gone bad, and may therefore carry dangerous pathogens. But many fermented foods (which are technically decayed) are totally safe to eat and even contain beneficial bacteria. People have no natural instinct for telling “good” decay and “bad” decay apart, so they rely on the process of acquiring taste to learn what’s good to eat. This also applies to bitter flavors, which are present in toxic plants as well as nutritious vegetables.

Rozin says, “We can’t just eat sweet things and avoid bitter things, so we have to have a way of acquiring taste, and that way is based on our experience of the taste and the consequences of the taste.” Thousands of years ago, that meant figuring out which foods were safe through trial and error. Fortunately, our ancestors have already done the hard work of differentiating the poisonous plants in the woods from the safe ones.

But even if we know the kale on our plate won’t kill us, we still need to go through the gradual process of acquiring the taste for our brains to accept it as safe. “If you’re a modern human, the culture has already vetted what’s safe—you’re not going to get anything you can’t eat from the supermarket,” Rozin says. “So you are acquiring taste, but you’re acquiring them by exposure or other mechanisms.”

How to Acquire a Taste

Acquiring tastes is a natural part of human development, but many adults still can’t stomach certain flavors. For people who want to overcome their food phobias, “hacking” the psychology of acquired taste is possible.

Rozin has experienced this firsthand. “I’ve done it myself,” he says. “I’m very bitter sensitive, and I didn’t like beer for a long time and I kept working at it. That’s also true of hot pepper, which I didn’t like originally, but I worked years to get to like it.”

So if you’re someone who wants to like raw oysters, for instance, your best course of action is exposure to it. Just make sure to eat them with plenty of condiments around people who already like them.