"[In Massachusetts], 61 percent admit to swearing, honking, or being vocal at other drivers, and 42 percent often experience road rage." So actually Massachusetts is just the least dishonest state.
tbh having driven in several states of New England, I would expect MA and NJ to be high on the list of "most rude" just based on the psychological effect on driving on their roads regularly
MA roads, especially in cities, train you into a very "every driver for themself" mentality. They frequently set up ambushes where you can barely see other drivers coming, make it really easy to get confused and lost or miss turns, and greater Boston especially is laid out like it's designed to start fights.
NJ roads by contrast don't set you up to fight other drivers so much as they train you not to trust the roads themselves, but that means other drivers are an unwelcome distraction/threat/environmental hazard and you just wish everyone else would go the fuck away so you can deal with the real problem, which is that the roads are out to get you.
NJ drivers also get pissed because during shore tourism season they get all the guys camping in the left line. That’s the fine money lane not the Sunday driver lane.
Like how I'm riding in the middle lanes and people are passing me on the right despite the passing lane being wide open... yes, please... pass me on the blind side