Socs and greasers show that they belong partly by dressing and wearing their hair alike. Dressing in common is a way of demonstrating camaraderie and commonality. Pony says that while the greasers “steal things and … hold up gas stations and have a gang fight once in a while” (Ch. 1), what makes them greasers is mostly the fact that they come from the same neighborhood and behave in similar ways.
I only mean that most greasers do things like that, just like we wear our hair long and dress in blue jeans and T-shirts, or leave our shirttails out and wear leather jackets and tennis shoes or boots. (Ch. 1)
Socs, on the other hand, dress in a preppier style. They wear a “madras shirt” which is a collared, button down shirt, often plaid. They are also described as wearing “checkered” shirts, sweaters, or madras ski jackets.
Socs stick together because they are all wealthy and privileged. They do not fit in with the greasers. Ponyboy expresses frustration because the Socs are always fighting the greasers, but even if they win against the Socs, they never really win. The Socs have won in life.
And you can't win against them no matter how hard you try, because they've got all the breaks and even whipping them isn't going to change that fact. (Ch. 1)
The Socs and the greasers are competing against each other not just in their gang war, but in life.
Why did the Socs hate us so much? We left them alone. I nearly went to sleep over my homework trying to figure it out. (Ch. 1)
A good way to end your essay is to summarize the themes of your essay. The theme of the essay here is that both the Socs and the greasers are acting the way they do because they are fulfilling the roles they were born into, regardless of what they actually want to do, and they continue because they get into the cycle violence because of their need to belong.