I’ve been a vegetarian my entire life. No one in my family or anyone I knew was vegetarian; it was something I came to on my own. When I was a child, people would often ask me why I didn’t eat meat, as if there was some moment or reason that precipitated it, but I never had an answer. Today I can name a whole host of reasons to be a vegetarian—ethical, health-related, and environmental—but I wasn’t aware of those benefits of vegetarianism when I was four years old. Yet as far back as I can remember, I’ve had an instinctual disgust toward meat. It was as though I was born a vegetarian. But is that possible? Are certain people natural vegetarians?
I never had an explanation until recent years when I learned about evolutionary psychology. Basically, just about every modern human behavior can be traced back to an evolutionary reason that served as a survival advantage for our prehistoric ancestors who lived in tribes as hunter-gatherers. I realized my social anxiety and shyness were the result of evolutionary psychology, which got me thinking: Could it be the same case with my revulsion toward meat? Is there a “vegetarian gene” in humans? An evolutionary reason I won’t eat meat?
Most humans are omnivores and are quite adaptable with their diet, able to digest just about anything depending on the environment and what’s available to eat—which makes complete sense. Humans thrived evolutionarily because of this ability to digest a vast array of foods. If a species could only eat a certain food and that food disappeared or died out, so too would that species. However, there would theoretically also be an evolutionary advantage to have a small percentage of a species retain a selective diet and abstain from certain foods.
For example, if a tribe of humans ate meat contaminated with a deadly virus or bacteria, the entire tribe would die out. But if there were a few vegetarians in the tribe who never ate meat, they would have survived in such a scenario. Therefore, evolution could have naturally selected for a small percentage of humans to have a natural disgust toward eating meat. Likewise, evolution might also naturally select for the vice versa—a certain percentage of people who eat only meat and are disgusted by fruits and vegetables. Then, if a tribe of humans ate a bad batch of berries, at least some members of the tribe would survive. It would benefit most people to be extremely flexible in their diets and eat all kinds of foods, but it would also be beneficial to maintain small minorities of the population who are extremely selective in their diets, always avoiding certain types of food.
This explains why I still have a revulsion toward vegan faux-meats. Even though they are 100% vegetarian, I am still disgusted by them because they look and smell like meat. Ironically, I also had a disgust toward fresh fruits and vegetables as a child, eating mostly pizza and processed junk food. I eventually got over that and now eat any and all kinds of fresh fruits and vegetables, yet I remain as repelled by meat as ever. I don’t see that disgust ever going away, which leads me to believe it is innate.
The elegance of evolution is astounding. DNA develops mutations resulting in different traits and characteristics, and if an organism with a certain trait (such as natural vegetarianism) survives long enough to reproduce, then that trait was evidently beneficial and will be passed on to the organism’s offspring. If that organism doesn’t survive and reproduce, then their unique genetic traits will die with them. Revulsion towards meat may be one such genetic mutation naturally selected for by evolution because of its potential survival advantage.
For some people, choosing not to eat meat is a moral and ethical choice, but for others, it may not be a choice at all. Vegetarianism may be wired into their DNA by evolution.