The jobs give students extra money to spend on gas for the car and money to save. Many students are part of a social group. Although Americans are independent and private about their time, there is a strong need for membership, as an association or connection. People in the social group usually have a lot of interests in common. If you like sports, you may become friends with people who practice your sport.
Every academic major has different types of groups.
It is difficult to be a member of several groups at one time, and it is difficult to change groups once you have become a member of one. You may find it is difficult to become part of a group. Each group has its unwritten rules. They have developed their own subculture of what is good and bad - and what the boundaries of behavior are. The penalties for not conforming are loss of reputation, or popularity or both, and of course, loss of group status.