The expression is reminiscent of the Billy Joel song New York State of Mind.
Being in a certain state of mind – described by some geographic locale – means to be comfortable with, and at ease in, that local culture.
For example, in the U.S., the Boston - New York area of the northeast is known for its hustle and bustle. Parts of the south are known for a more relaxed pace of life, and "southern hospitality." Some places along the Pacific northwest are known for an "organic" and environmentally-friendly lifestyle. In Texas, bigger is better.
The author here is just stating that life is different (perhaps more accurately, the culture and the mindsets of the people are different) in the New England college town than in the area around the graduate school out West.
From that passage alone, I'd surmise that the two locations – the New England college town, and the graduate school out west – were different in many ways. Perhaps one was in a big city, and the other in a more rural environment. Yet I think the passage also implies that the contrast runs a little deeper than typical urban-rural differences, with differences in the local color as well, such as how people generally interact with each other.