Essentially anything outside of your personal comfort zone that makes you twitch and have the reaction of acting nasty towards those who are different than you is xenophobia.
Humans have an inherent and instinctive reaction to things which are unfamiliar. It’s a survival mechanism for our species. It’s how we figured out what animals to stay away from and what plants we shouldn’t eat as we began to emerge from the mists of the paleolithic period in history and it’s how we stuck together in our own social groups as homo sapiens further evolved and developed distinctive appearances, and ethnic and cultural norms. When you had to stay with your own clan because none of the other clans of people trusted each other, we learned to fear those who weren’t in our ‘home group’.
So that part of it is inborn. We have a part of our brain that functions like this, but in a well-adjusted, intelligent person this isn’t the part in control. We’ve grown out of that mode of thinking and our brains have evolved into being capable of reason and emotion that aren’t just centered on basic needs for survival.
There’s something wrong with the brains of people who let that sort of instinct rule their lives, and it’s worse when they teach their children to rely on it.
We no longer live in a society where we need this sort of instinct to survive. We don’t need to worry about what might be out there when we go foraging for long periods of time, tracking down the mammoth to bring back to our group for food.
We know that there are other people out there in the world who are maybe not exactly the same as us, but we know that they aren’t going to kill us for food. We live in society with those who aren’t exactly the same as us, either they have a different language, or skin color, or cultural background, but we know that they are people.
We know that if we go out where wild animals and predators might be, that we should protect ourselves and we know what’s out there. Even if you live in an area with bears, wolves, and wild cats, you still KNOW that there are bears, wolves, and wild cats out there and you know how to avoid them.
Or you should go, and let natural selection sort you out of the human gene pool.
Purely for the good of our species offspring, of course.
If my tone comes across as snarky, it’s because xenophobia deserves ridicule.
It has no place in an intelligent, progressive culture and when it pops up, it only causes problems. Racism, sexism, and fear/hatred towards those of a different gender identity or sexual orientation, or pretty much any form of prejudicial discrimination you can think of has roots in the reptilian brain that some people so desperately want to cling to.
It’s wrong to hate or fear outright those who are different than you. It serves no good purpose. It’s a left-over relic from our prehistoric evolution that needs to finally find a place in the past so that we can move forward into a future where this kind of thing doesn’t exist.