[Serious]Why do people hate the unions?

It doesn't taste the same to them as it does to you. To get a sense of this, imagine putting cow dung in your mouth. Now imagine that's what you tasted every time you ate an onion. That's roughly what happens to them.

If you're tempted to say, "But onions don't taste like cow dung," all I can respond is, "Yes, I know they don't taste that way to you." You have different taste buds and brains than your friends. The taste of an onion is not located inside it. It's located inside the brains of people who eat it. Sure, the onion has properties--chemicals and textures our sense organs can detect. But how each brain interprets those properties is up to the brains, not the onions.

It's likely we developed taste because it helped our ancestors eat foods that were good for them and avoid poisonous ones. So whenever you get that yuck feeling, it's Evolution's way of saying, "Don't eat that! It will make you sick!"

I know that seems odd, because many people dislike tastes that are no threat to them at all. I hate the taste of mustard, even tough eating it won't kill me.

But you have to remember that modern life has plucked us out of our ancestral environment. We still have the brains and bodies of our ancestors from 50,000 years ago, and if a taste indicated something was poisonous to them, we may still gag at it, whether or not it's a problem for us.

The way Evolution works is that traits which cause organisms to survive and produce healthy children tend to get passed on. Traits that lead to death and no-mating tend to vanish, because there are no children to inherit them.

This suggests that many traits just need to be "good enough" to promote survival and reproduction. They don't have to be perfect.

For instance, imagine a bunch of "cave men" growing up near some woods where a particular plant was poisonous and could kill them. Let's say some of these early humans had a genetic mutation that made them hate the taste of those plants. Others liked the taste or could take it or leave it. The mutants had an advantage. On average, they outlived and out-mated their non-mutated cousins. They had more kids than the others, to which they passed on their mutation. Which their kids passed on to their kids, and so on.

Now, let's imagine there were other plants in that same woods that were perfectly safe, but which tasted similar to the poisonous ones. Yes, the mutants needlessly avoided them, too, but so what? Assuming there were other sources of nourishment, they still had an advantage.

My point is that a taste may have evolved because it protected our ancestors from poison, but that doesn't mean all food items with that taste are poisonous. It just means that avoiding it tended to increase one's changes of surviving and mating.

But why do tastes differ? Well, our species quickly spread all over the planet, into many different environments. Tastes that correlated with poison in one place didn't necessarily correlate with it somewhere else. So different populations developed different tastes--each group developing ones that would increase their chances of survival and reproduction wherever they lived.

You and I are descended from different groups of people, which may be one of the reasons we have different tastes. You can actually see differences in the number of taste buds that different groups of people have. Some groups are better at detecting bitter; some are better at detecting sweet; etc.

But there's more to the story: one of the reasons our species has adapted so well and so quickly, to so many different environments, is that we are highly malleable to cultural (as opposed to evolutionary) pressures. Often, a preference is malleable at first but hardens later.

An example is language. A toddler can easily learn any language. But once he reaches a certain age, it becomes much harder--at least to learn it like a native. Taste is similar. If you're exposed to certain foods as a child, they will taste better to you than to someone who didn't taste them (or didn't taste them often) until he was older. Perhaps you ate more oniony foods as a kid than your friends. As a result, onions now taste different to you than they do to them.

This plasticity makes sense. A child who can learn what's healthy and dangerous--where he lives--has an advantage over one who can't. If no one fed onions to your friends when they were little, their brains decided, "That must be because oniony tastes are dangerous."

I've heard some anecdotal evidence that with perseverance, at least some people can reverse the taste-aversions they learned as kids. What they have to do is keep eating foods that disgust them--over and over, for a long period of time. After many exposures, they may come to like those tastes.

/r/AskReddit Thread