I wish you'd been around when I was a kid and everyone was trying to force me to eat stuff.

I am totally not an anthropologist, so it could be wrong though.

I am partially not an anthropologist, and partially not a foodways nerd.

That's an idea I've seen batted around some in anthro texts, in evolutionary psychology, and in foodways: that certain alkaloids and potent or pungent flavors (and especially unfamiliar ones) are rejected by young organisms as a self-protective measure.

I've never seen an in-depth discussion of the idea, though, and I've yet to read a cross-cultural study of childhood food aversions, much less a cross-species one. But I'd love to see such a thing if it exists! Off the top of my head, I'd say cross-cultural and cross-species studies would be the first place I'd look to see if the idea is supportable.

I think there's probably no one explanation for "picky eating," but a complex web of reasons. Some may be biological, some cultural, some familial, but I suspect that in many cases (at least in most North American households) it's partly an assertion of independence or choice. In some cases, that's the one thing a child can totally control: what s/he eats.

What JanetLand said.

I cannot, not not eat anything remotely spicy. Mild salsa is the limit for me. I was also a fairly picky eater in general as a kid (still have a fairly boring palate, give me macaroni and cheese any day); my parents were liberated foodies (in one of those liberal ground-zero cities) who were bewildered that I, at 6, did not care for their amazing creation of an Indonesian rice dish. If I were Mexican, I'd be dead by now. In the spirit of wanting to fit in my tribe (something we're wired to do) I tried my darndest, but it was, and is, so painful that it's just impossible.

My guess is that my ancestry, nominally German/Lithuanian/Jewish and Irish/English, accounts for that, and that some of us are just wired to be in our native region (f'ed up by so many of us moving to North America) and nowhere else. Doesn't account for my mom, tho, who's German/Jewish and Lithuanian/Jewish. Hmmm.

I've yet to read a cross-cultural study of childhood food aversions

My suspicion is that it's not something you'd come across much, except in the historically somewhat rare situation of continuous food abundance.

After all, caution is different from pickiness. I've seen some theorizing about risk-taking behavior that posits that populations produce a certain small percentage of people who are risk-takers, and those people serve as the canaries in the coal mine for everyone else. In other words, if someone's going to walk into the enemy camp to negotiate, if someone's going to cross the mountain range to see if there's good stuff on the other side, if someone's going to go to see in a rickety boat, if someone's going to eat that weird-looking red berry - it's going to be the risk-tolerant people. And everyone will watch their results before adopting their behavior.

This goes some way toward explaining why some portion of people want to do shit like become a pilot or an astronaut, BASE jump, or do other extreme stuff. If a population has these risk-seeking people, it doesn't need picky eaters, because the risk-seeking people will be the first ones to step forward and try a suspicious food. Everyone else will base their estimation of that food's safety on the results.

So I think this is a lot more likely than that pickiness is somehow selected for. There are so few situations in human history in which pickiness would be an advantage that I doubt it is hardwired. When food is scarce, ideas about pickiness disappear. I think pickiness is therefore only associated with abundance, and then where there's abundance ideas like choice and can control by a food recipient can come into play. Until there's abundance and some degree of autonomy on the part of the recipient, someone who needs food is in no position to pick and choose about it.

...and people can be picky - in fact, they pretty much always are picky - about foods that have been demonstrated to be safe to eat beyond all doubt. So as a mechanism to identify foods safe to eat, it's no good at all.

Apparently populations and birth rates increased after agriculture was invented, in part because now you could feed the kids on mushed cereal, you could wean them earlier and no longer have the contraceptive effect of breastfeeding.

So a preference for bland mush might be favoured by evolution if it's more likely to give you siblings with the same genes.

However: when I was a kid, we weren't allowed to eat between meals. If we didn't eat our dinner, there wasn't going to be any more food till the next meal, and that wasn't necessarily going to be any more likeable. So anecdotally, I suspect "eat this or go hungry" discourages fussy eating: I certainly ate everything they put in front of me.

I remember reading someplace that picky eating became a desirable evolutionary trait because as babies became toddlers and were able to wander away from their mothers, picky eating helped limit what they might put into their mouths on their own, when no one might be watching. Makes sense, in a way .. if a 2 year old doesn't want to try new things, it might be ingrained in a sort of "this new and unknown food might actually kill you so better stick with what you know" thing in her genes.

But that still wouldn't explain why pickiness would persist after the food has been shown to be safe and can no longer be thought of as 'unknown.'

My own experience matches Theophile's. Unplanned snacking didn't exist in my household as a kid, and we did not have alternative choices at meals - what was for dinner was the menu, and that was that, and dessert only for those who finished their meals. There were foods I didn't like and tried to avoid, but for the most part I found that being picky didn't give me any advantages. However, my brother, who was chronically underweight as a kid, refused to eat certain foods completely, and because my mother became concerned about just getting calories into him, he gained more power over the menu than I ever had - by high school he was making his own egg nogs and french fries as after school snacks and getting a pass on foods he didn't like, which included a lot of things, entire groups of food like cheese, butter, fish, chicken, and most vegetables. He really did need the calories and was as stubborn as all-get-out, so I understand why the rules got relaxed for him.

I've shared meals with literally more than 10,000 kids over my years of residential teaching and summer camp, places with limited menus and limited controlled choice, and have seen that even picky kids will eat when they're hungry. They'll find something.

So as with most behaviors influenced by selection, I suspect that some amount of pickiness may be inborn, and may emerge when there are choices in the environment and the possibility of manipulating the people who determine those choices, but can be encouraged or discouraged by environmental variables and may not exhibit itself at all.

The really picky eater I know is also the person I know with the longest list of allergies (food and environmental). I've wondered if this might be a defense mechanism of some kind.

I had a childhood with "you eat this or you go hungry." I recall a few instances of just not eating main or side dishes. Usually this was our mom trying to sneak spicier elements into things like tomato-based pasta sauce (to "prove" to us that we could eat it), and getting angry when it didn't work: we tasted it and didn't like it. She'd say SHE couldn't taste anything bad at all, so obviously we couldn't either, and we had to eat it or eat nothing. Yeah. It was awful and we didn't eat it and we didn't get anything else instead. It's not like we were otherwise underfed, so we didn't starve, just missed an entree or something every so often.

Now that I get to choose my own meals, they're a lot less likely to be combative and I'm much more interested in expanding my horizons by choice, rather than by force or by subterfuge.

I feel like I should also add that the combative approach to food ("you eat at mealtimes, you eat what I make, or you get nothing") was really, really bad for my health as a kid. My body wants high-protein mini-meals 6 times a day. I was fed high-carb big meals 3 times a day. This was really bad for my energy levels and caused constant headaches. The one-size-fits-all meals were a surprisingly bad idea.

Now I'm hungry.