I grew up in a family of six, with three younger siblings. One of the most stressful, and yet memorable parts of my childhood is family meals. Absolutely none of us liked the same types of food. Of course, there were a few things I didn’t particularly enjoy the taste of at a young age, most of which I still dislike, save a few tastes I now crave on a daily basis. I still can’t stand salad, cold lunch meat, peppers, or cantaloupe… however, I have gone through the natural progression of begrudgingly learning to love vegetables, a few types of sauces and spices, and even certain obscure cultural foods of other areas of the world. However, absolutely nothing I experienced compared to that of my younger brother. My brother Jack is just two years younger than I am, and his childhood was completely transformed by his extreme picky eating. From the age of three to about 14, he essentially lived off of chicken nuggets, peanut butter, apples, cereal, and sweets. We tried everything in the book, with nothing prevailing. 
I even vividly remember trying to sneak a pear slice into his plate of apple slices, just so that he would try it, and he immediately noticed before it even touched his tongue and I was honestly so frustrated. How could a growing boy evolve into a man without having a slice of pizza, or a hamburger? He managed to do it.
It wasn’t just that he disliked a lot of different foods because he either refused to try them, or hated the taste. It was that he truly did not like the act of eating. He felt as though it was a chore, and we had to do all but force him to sit still at the table and put down a full meal, even if it was the exact same thing he’s eaten every night. Unsurprisingly, he went through his childhood the size of a twig. However, in the past three years, he has gone through an amazing transformation. Today, he will eat close to ten times the types of foods he was willing to try before, and in bulk. He looks forward to meals, and gets all of his vitamins in that he needs. He’s probably grown close to a foot just having finally expanded his food horizons. He even is willing to try new things; he constantly asks to order something different at a restaurant, or take a bite of someone else’s meal. Having firsthand witnessed this experience, I’ve often wondered, what makes a person evolve to love the food that they would refuse to even be in the same room with as a child?
Through some research, it essentially comes down to science, shown through a handful of factors. The first major player in our food preferences is innate, and it all starts with genetics. According to an article by author Joseph Bennington-Castro on the psychology of food tastes, as humans, we all are predisposed to 
enjoy a few particular tastes for evolutionary reasons. Fatty food attracts us for its high calorie count, providing us with the energy to get through the day. Sweet food often attracts us for its energy as well, along with nutrients and vitamins. On the other hand, tastes that are bitter are historically prevalent in toxic plants, so we are genetically predisposed to despise them (Bennington-Castro). However, genetics don’t play an overbearing role in our psychological predisposition to enjoy and dislike particular foods.
In fact, the majority of our preferences are actually learned, sometimes before an infant is actually born. Apparently, within the womb, infants are often influenced by the mother’s daily eating habits, so that whatever tastes they are often predisposed to, they have been shown to have greater positive reactions to after birth. In one study, as detailed by Bennington-Castro, mothers regularly drank carrot juice late in the stages of their pregnancy. After birth, psychologists found that these babies tended to enjoy carrot-flavored milk and cereal more than their non-carrot-drinking counterparts (Bennington-Castro). Following birth, an infant will essentially eat anything for a period of around two years (Bennington-Castro). Directly following this, children often develop neophobia, developing a dislike for any new food.
Often, parents take this period of time and give up altogether on trying to force their children to eat the food they will throw a tantrum at the sight of (Bennington-Castro). However, this is often the solution to avoiding a picky eater. Children must habitually eat the things that they may dislike, because later, this neophobia will subside, and they will learn to love it. Additionally, I believe that sometimes, cultural influences affect your willingness to try food. I genuinely think that my brother eventually got so sick of having to be the one who needed a special order at a restaurant or who couldn’t eat the slice of pizza at the pool party that he forced himself to try and like those things that he was afraid of. It simply takes time, people will learn to adapt after passing this initial neophobic age, and realize their true tastes. Expanded horizons are a positive thing, and most will develop an ever-expanding palate as they age. If you want to check out a video that teaches you to overcome a taste aversion, you can find it here.
Bennington-Castro, J. (2013, April 22). The psychology of hating food (and how we learn to love it). Retrieved September 16, 2016, from http://io9.gizmodo.com/the-psychology-of-hating-food-and-how-we-learn-to-love-476720251
This post really interested me because I had a very close friend who still deals with a situation similar to your brother. When we were younger it was so extreme that she wouldn’t even try a hotdog, and she didn’t like pasta with sauce. She lived off chicken fingers, french fries, and pasta with butter. At the time I was jealous of her because if it was up to me instead of my parents that’s what I would have eaten. As my friend grew older her selection of choice foods slightly, but it wasn’t until she had to see a nutritionist that she really progressed. The nutritionist informed her that she had an eating disorder known as avoidant/restrictive food intake disorder (ARFID). She was diagnosed with this disorder because she avoids food based on colors or textures. In order to try and work past the disorder she regularly meets with her nutritionist and attends group support meetings.
To read more about other forms of ARFID you can read about it from The Center for Eating Disorders:
http://eatingdisorder.org/eating-disorder-information/avoidantrestrictive-food-intake-disorder-arfid/
I’ve been a picky eater my entire life. I’m 18 years old and still eat like a 5th grader, preferring chicken fingers and mac n’ cheese to anything slightly fancier. I am opposed to trying any new, exotic foods mostly because they just don’t look appealing to me. My family has always chalked it up to the fact that my mom craved the most generic, unhealthy food when she was pregnant with me so it’s interesting to learn from your post that this theory might actually be true. I found an article that explains additional reasons and causes to picky eating. Check it out here.
Growing up my cousins were the pickiest eaters. They usually chose McDonald’s over any home-cooked meal. It was mind blowing to me that they wouldn’t even try the food set out for a meal. They would reject the food before even tasting it. Looking back, their eating habits mimicked that of my aunt’s. She was extremely specific about the foods she would eat, and it may be possible that my cousins just copied the habits they grew up seeing. Contrastingly, my parents will try anything at least once when it comes to food despite smell or appearance. My parents always encouraged my sister and I to take a bite of their food when we would go out to eat and to order something new at a restaurant. Comparing my cousins’ habits to that of mine and my sister’s, it’s fair to assert that choosing or rejecting certain foods is a learned behavior in addition to genetic predisposition.
I can relate to the development of a persons taste buds. Growing up I hated chicken and vegetable, now I eat them voluntarily almost every day. Its interesting to observe how a persons taste buds change over the course of their life. Heres an article describing how tastebuds work along with their purpose. https://kidshealth.org/en/kids/taste-buds.html
I have never been a picky eater but I had a friend who all throughout high school would be hard pressed to eat anything other than chicken nuggets. I was always shocked that she could really just not like anything else. I think that a lot of it has to do with the ability to step out of your comfort zone, as seen here http://lifehacker.com/the-science-of-breaking-out-of-your-comfort-zone-and-w-656426705