* Social Class Tension: The Socs and Greasers represent two distinct social classes, each with their own prejudices and stereotypes. The Socs, being wealthy and privileged, often looked down upon the Greasers, who were considered lower class and rebellious. This inherent tension fueled their rivalry and aggression.
* Previous Encounters: The Socs had a history of harassing and bullying the Greasers, including a fight earlier in the book where Ponyboy was jumped by a group of Socs. This history of violence created a sense of animosity and a desire for revenge.
* Misunderstanding and Stereotyping: Ponyboy and Johnny were seen as part of the "greaser" stereotype, which the Socs associated with violence, delinquency, and a lack of respect for authority. Even though Ponyboy and Johnny were not inherently bad, they were seen as a threat due to their social status and perceived behavior.
* Bob Sheldon's Death: This is the most significant reason. The Socs, particularly Dallas Winston, believed that Ponyboy and Johnny were responsible for the death of Bob Sheldon, a Soc. This accusation, even though unfounded, fueled the Socs' anger and made them determined to seek revenge.
It's important to note that while the Socs were portrayed as the antagonists in the book, they were not inherently evil. They were misguided by their privileged backgrounds and their own set of social expectations, leading to their hostility and prejudice towards the Greasers.