I just started a new job as an intern. I am actually on my second week, and I think I have been getting along pretty well with my team. Everyone in my team likes to take long lunches; hour to a hour and a half, and they are purely social in nature. For the first week I went along with them, but I personally prefer to take a short lunch, and leave work sooner. For the past two days I didn't go out with my team to eat, and I feel fine about it other than the fact that this behavior might distance me from my team. 

I get paid based on the number of hours I work, but it is based on honor system, so no one is keeping track of it but me.