I ate pig cheeks last night. We'd just arrived in the small, medieval town of Evora, Portugal, renowned for its hearty cuisine and wines. I'm someone who leans vegetarian, so pig cheeks were the last thing I was craving. But sticking to my Portugal road trip policy of openness and zero expectations -- and with our waiter insisting that pork cheeks are the best fare in the region -- I leapt.
I've actually always been fairly game for trying weird foods in my travels, and as I watched my 6-month-old son devour his second solid meal ever -- pureed carrots -- across the table from my pork cheek extravaganza, I wondered if the trait is partly genetic.
Yes it is -- at least, according to a 2007 study in the American Journal of Clinical Nutrition (AJCN), which examined food neophobia -- the fear of new foods -- and its genetic origins. The researchers surveyed the parents of 5,390 different pairs of twins about their children's willingness to try new cuisine. It turned out that the identical twins were much more likely to share food aversions than the non-identical twins. Identical twins share all of their genes; non-identical share only about half that. So the researchers concluded that food neophobia is largely genetic, perhaps as inheritable as height, according to Jane Wardle, director of the Health Behavior Unit at University College London, one of the study's authors.
Other experts think eating habits are more learned. "It can't all be genetics," Marcy Goldsmith, a nutrition and behavior specialist at Tufts University, told the Associated Press in regard to the AJCN study. "Parents need to offer their children new foods so they at least have a chance to try it."
It would be plain crazy to say openness to food isn't partly learned. Travel through Oaxaca, Mexico, for example, and you'll meet tons of kids whose favorite food is fried crickets -- "chapulines" -- but you'd be hard-pressed to find many kids in the United States who wouldn't find the idea of eating even a single cricket repulsive. Our environment certainly shapes our eating habits, and the authors of the AJCN study don't deny that. They simply argue that genes are far more influential, having a 78 percent influence on food neophobia, with environmental factors only responsible for 22 percent.
More studies need to be done before we can make any definitive statements on the matter, but I find this genetic theory more convincing than the oft-cited theory that willingness to try new foods is an extension of human openness to any new experience. Under this theory, people who tend to crave new experiences of all kinds (so-called High Sensation Seekers on the famous Zuckerman-Kuhlman Sensation Seeking Scale) would also be more open to new foods. Hence, shy kids would be more prone to food neophobia and outgoing kids would be more willing to eat anything.
There may be some truth to this. Zuckerman has shown that one's sensation seeking level is a highly heritable trait too (about 60 percent, according to other studies of twins), but having done the sensation seeking questionnaire myself, I think the questions (such as, "True or false: 'I do not worry about unimportant things'") are a little too general to be used in the case of food. Frankly, I think this an example of why the scale is somewhat flawed.
As just one example, I have a dear friend -- I'll call him J -- who has a food phobia and has thus eaten little more than pizza and beef his whole life. J is extremely intelligent (he literally scored a perfect on his SATs) and has turned his phobia into a passion for pizza that rivals any Neopolitan pizza chef's. J can not only cook the best pizza you've ever had. He can tell you where to get a good slice just about anywhere on earth -- and he knows this because he is a classic High Sensation Seeking personality, constantly seeking new travel experiences, new social encounters. To top it off, he loves surfing. The thing he fears deeply, however, is greens. During his bachelor party, in fact, one of the challenges he had to complete -- along with numerous embarrassing public displays of male ridiculousness -- was eating a salad. Walking up to strange women and making a fool of himself wasn't the least bit difficult for him, but you could see genuine anxiety rise up when the salad plate came out. He practically swallowed the leaves whole, downing them with gulps of beer.
Experience tells us that J is far from alone in being a High Sensation Seeking food neophobic. The other extremely food-reticent person I know (a big character in the coming Fear Project book), is Jamie Patrick, a professional adventure swimmer who recently nearly killed himself swimming twice, nonstop, across Lake Tahoe -- a distance of 44 miles. (Tell him that he's low on the Sensation Seeking Scale.) Now think of all those kids you know who love sensation-seeking sports or hobbies -- skateboarding, football, punk rock -- but wouldn't eat spinach if their lives depended on it.
So, in sum, I think this AJCN study is fascinating and well-crafted. It makes sense that food neophobia likely evolved (as the researchers state) to prevent mammals from eating poisonous foods. It makes sense that neophobia was important enough to our survival that it became a part of our DNA. And it also makes sense that openness to new foods was important enough to our survival -- diversifying our food sources, preventing disease, etc. -- that it also became part of our DNA. But I'd venture to guess that the gene(s) for food neophobia and food openness are separate from the genes that tend to lead to shyness (which has also been shown to have heavy genetic origins).
For example, I was a shy kid -- but I'm definitely eating the pig cheeks again before leaving Portugal.
For more on the science of fear, click here.
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For more on becoming fearless, click here.