Culture of an ER department

You are confusing culture with atmosphere.

No...I don't think I'd agree with that. It depends mostly on your team, and partially based on the firm. Granted, it's less interactive with colleagues than banking simply because the teams are smaller, but it's not like you're throwing parties all the time in banking either. I have seen certain teams that really keep to themselves, though.

Based on my experience at a couple of BB's, I can say that one of them was a lot of fun, whereas working at the other one was not. The reason the latter experience wasn't that fun was because a lot of people didn't like their jobs there, the overall culture of the firm was pretty poor in my view, and they had gone through a fairly sizable round of layoffs which definitely dampened the mood. Plus, I grew increasingly discontent with my boss, so much that I later moved to private equity and never looked back. In your words, I guess you could say that my first experience in research was a lot more engaging, whereas the latter was more "reflective of that of a library" because I basically lost interest in engaging with my boss -- he was too annoying and not competent enough.