I do believe a lot of it is learned, but some dislikes, I think, are inborn. My older son would/could not eat apples or pickles, because of the crunchiness. He would actually throw up from trying to eat the. He is still like this. He was an extremely picky eater as a small kid, and was always super skinny (still is). But, in high school, he had a lot of vegetarian friends, who introduced him to lots of ethnic foods that he would not eat at home. He now eats everything (except apples and pickles).