Different Majors, Different People Or How Dirt Changes Relationships

The other day I overheard a conversation between two of my roommates, a buisness major, and a law major. They were talking about manipulating there professors into becoming friends with them so that they could call their professors by their first names, and have lunch with them, etc. One of them was super excited because one of the emails they got back from their professor was only signed with their first name.
I couldn't help but laugh. All of those things have happened to me and I have in no way tried to create such a relationship. I don't think it has anything to do with me, and it has all to do with the majors. Granted, as a master's student you have more one on one interaction with professors, but even as an undergrad I had professors invite us to use their first names and talk about life with them. I remember specifically on the field school I attended my professor telling us that in the field we could call him by his first name, and another professor in our capstone class did the same.
So why is it different? I'm not sure but some of the reasons I could see for it is that the majors I've been in tend to be smaller (and thus more intimate), they include a more casual set of people (we like to dig in the dirt! how formal can you be?), they put less focus on appearances (dirt again!), and they usually have more opportunities to have informal interactions (time in the field... or in others words dirt).

Real formal, right?

I had known before that majors were different. There is a reason afterall, that there are sterotypes of engineers, english majors and business students. I just hadn't realized quite so much, that the people are genuinely different types of people. They look at the world differently and that is why they are perhaps, interested in the subjects that they are, because the very subject is a way of looking at the world.