Where you go to grad school (or undergrad) has a LOT to do with it. And some luck as well - Your dept might not have anybody you want to be friends with. But two years down the road might change everything.
That said, for me, I've met the most people at school mostly because I find myself surrounded by people who I can identify with. Its easy to make friends in a group of people who are like you, but if you don't feel like you fit in a group of grad students, its hard to make friends...
That said, for me, I've met the most people at school mostly because I find myself surrounded by people who I can identify with. Its easy to make friends in a group of people who are like you, but if you don't feel like you fit in a group of grad students, its hard to make friends...