I was surprised to find that this isn't the case with science or engineering graduate students, at least not at my grad school.

With a few exceptions, most are NOT geeks/hackers, and tend to use social interaction to escape thinking about technical things, not to geek out on them even harder than they do in the lab.

I've had better luck finding interesting and smart friends in artistic and psychedelic drug use subcultures, despite the fact that I have little interest in those activities myself.

I don't have a broad sample of what different schools are like, but mine is a large public research university in the southwestern United States.