Roughly a century ago, two researchers were working together in a DuPont chemical lab when one of them, Arthur L. Fox, spilled a bit of harmless phenylthiocarbamide dust. His colleague complained of the bitter taste in the air, but Fox tasted nothing — even after dabbing a bit of the dust onto his own tongue.
This experience inspired Fox to dig deeper into the science of taste, and his later work led to the discovery that, due to the presence or absence of certain genes, not everyone tastes bitter flavor compounds in the same way. Taste researchers working today use small squares of paper — coated with the same class of bitter compound that Fox let loose in his lab — to assess a person’s sensitivity to bitter flavor.
“When tasting bitter, 25% to 30% of us experience it in neon,” says Diane Catanzaro, a taste researcher and associate professor of psychology at Christopher Newport University in Virginia. By “in neon,” she means very intensely; these people are known as “supertasters.” On the flip side, about the same percentage of people are categorized as “non-tasters” because, Catanzaro says, “they’re basically taste-blind to bitter compounds.” The rest fall somewhere in between the two groups on the spectrum of bitter-taste sensitivity.
Some evidence has associated supertaster status with an aversion to certain foods — particularly fruits and vegetables that contain bitter compounds, such as brussels sprouts and broccoli. There’s also research linking some other genetic factors to specific taste perceptions. “A portion of the population finds that cilantro tastes soapy,” Catanzaro says. This happens, she says, because some people inherit olfactory receptor genes that are sensitive to the aldehyde flavor compounds found in both cilantro and soap. “It’s clear that we don’t all taste or experience the same flavor world,” she adds.
All of this suggests that picky eaters are born — not made. It makes sense that supertasters would be turned off by the bitter compounds in some foods, and that other genetic predispositions or disinclinations toward certain food textures or aromas could govern a person’s food preferences.
“What we taste is combined with aroma and mouthfeel, and this combination goes to the brain and has associations with memory and culture and exposure.”
But Catanzaro’s research argues otherwise. She and her colleagues tested people for sensitivity to bitter tastes, and then questioned them about their food preferences. They found no evidence that supertasters are more likely to be picky eaters than non-tasters. “We looked at the data every which way, and we did not find any consistent correlation between taster status and liking for certain foods,” she says. “Many picky eaters are non-tasters, and many supertasters eat everything.”
While there’s no doubt that different people perceive flavors in a variety of ways, these person-to-person discrepancies don’t seem to predict whether someone will be a picky eater. “Genes have an influence, but they’re not destiny,” she says. “What we taste is combined with aroma and mouthfeel, and this combination goes to the brain and has associations with memory and culture and exposure.” All of these factors, wrapped up together, determine what foods a person likes or doesn’t like, she says.
Childhood experiences surrounding food may have a particularly strongly influence how people eat later in life. “Almost all of the adults I’ve talked to or worked with who are picky eaters can trace their food problems back to early childhood,” says Dr. Katja Rowell, a family physician and co-author of Conquer Picky Eating for Teens and Adults.
It’s well established that food preferences evolve as people age, and that children tend to be drawn to foods that are salty and sweet, rather than sour or bitter. (This helps explain why so many kids don’t like eating vegetables.) “Half of children are described as picky eaters by their parents,” Rowell says. And that pickiness can lead to stress and conflict at mealtimes. “If you grew up in a family where you were force-fed sweet potatoes and vomited them up, that conflict or anxiety can poison your relationship with some foods,” she says.
It’s also possible that if a person grew up in an environment in which mealtimes were filled with arguments of conflict, they may associate eating with stress. This can steer them toward food choices that feel safe and predictable, rather than new and potentially unpleasant ones, Rowell says.
Other variables also seem to influence a person’s food preferences. A 2015 study published in the journal Appetite found higher rates of picky eating among people with certain mental health disorders, including obsessive compulsive disorder (OCD) It’s not clear exactly how the two are related, but it may be that some underlying personality characteristics — such as “behavioral or cognitive rigidity” — could play into both OCD and picky eating, the authors of that study write.
Catanzaro says exposure, observational learning, and classical conditioning also play a role in pickiness. “If you grew up in the Midwest eating meat and potatoes every night, the blandness of the food environment is going to condition you to like certain foods,” she says. Meanwhile, a child who grew up eating a lot of spicy food in southern India is going to feel comfortable with that kind of fare, she adds.
To sum all this up, the biological, environmental, and experiential factors that shape a person’s pickiness are manifold. And, likewise, the process of overcoming a picky eating habit is often complicated. “There is no straightforward or simple strategy to overcome this eating tendency once it’s established, even for those who are motivated,” Catanzaro says. But she says exposure to new foods — albeit incremental and cautious exposure — is one way for some picky eaters to broaden their food horizons. “The more we’re exposed to something, the more we tend to like it,” she says.
Rowell mentions a client who had never eaten apples. “We started with wafer-thin slices — some with the peel on and some with the peel off — and agreed ahead of time that she could spit it out if she wanted,” Rowell recalls. “She discovered that larger bites made her gag less than the really thin ones.”
Another method she uses is called “bridging.” This involves taking foods a person likes — say, grilled chicken — and using that as a springboard into new foods. For example, a person could try dipping the grilled chicken in a new sauce, or pairing it with avocado, she says.
But these tactics don’t work for every picky eater. Rowell mentions an eating disorder called avoidant restrictive food intake disorder (ARFID), which can lead to nutritional shortfalls or problems maintaining a healthy weight. She also says some people are overwhelmed with anxiety during mealtimes, or may not be able to help gagging or throwing up when eating certain foods. For these sorts of eaters, simply trying new foods isn’t going to cut it. They need a counselor or therapist’s guidance to address their food-related anxieties.
One thing that’s not helpful, Rowell says, is a friend or loved on who makes a picky eater feel silly or ashamed about their eating habits. “Someone who makes you feel guilty, or says you’re spoiled or should ‘just try it’ — that is really not helpful,” she says. These sorts of comments — or pressuring someone to be less picky — can recreate the kind of anxiety that could have kickstarted a person’s pickiness in childhood. On the other hand, finding an “eating buddy” who understands how challenging it can be to try new foods — and who doesn’t apply pressure or judgment — can be super helpful, she adds.
“With picky eating, like anything else, there’s variance,” Catanzaro says. “You meet some people who are more cautious, and some who are more adventurous.”