fit in ( v ) - Be suited to, belong.
Belong where?
It may have occurred to you that one very important task for many teenagers is to "fit in with the popular crowd". Who are they? Why do they seem like teen royalty?

Let's take a look at a wannabes diary:
"7:30 A.M - High school - popular crowd is going down the hallway. Like lions among zebras, all those who are not "popular" (like me) steps aside.
They're predators - if you don't do as they say - they bite (and they bite hard). In one second they could turn you from a semi-popular teenager, to a herb eater at the bottom of the food chain...
It reminds me of the one time I had ice cream with my family at the port, and they spotted me! That was so embarrassing! The next day, Miranda (the most popular girl at school in case you didn't know) called me fat. I'll never eat ice cream ever again! And must never be seen hanging out with my family!"

Seems pathetic right? Hurts as it may sound, such thought aren't rare, in fact, they're quite common among teenagers.
But who doesn't want to fit in? And not just withing the "popular crowd" but with any group! Humans are social beings and we need society to keep us company.
Ever since humanity began, humans have been creating social groups that started with families, tribes and eventually kingdoms. (Which indicates our basic need for social environment).
Then fitting in with a group that seems like royalty and so glamorous, or any other group, seems like taking care of a basic need.

Why do those teenagers seem like royalty?
According to the french philosopher, Jean-Jacques Rousseau, human society is very territorial. As he wrote in his book "Discourse on Inequality": The first man who had fenced in a piece of land, said "This is mine," and found people naïve enough to believe him, that man was the true founder of civil society".
We have seemed to run into a situation where a person whopossess something and claims it, becomes a ruler.
Same thing goes with high school.
Let's take our usual high school popular girl and describe her: huge ego and follows a certain standard that most popular girls have to follow (like a certain type of hair and clothing, certain bags and outfits).
She claims a crown, the high school crown. The crown shows that she's the queen of the school, therefore she's popular, because she crowns herself.

Have you ever noticed that at least 95 percent of the girls who are part of the popular crowd dress up the same way? Next thing you know, you will be judged by yout blood type.
Why can't anyone see that we're all humans? That we're equal! No matter how we're labeled in high school, remember that they, just like you, are humans.