Decades ago I discovered what seem to me to be a unique Boston driver behavior. It is called the Boston Pullout. Here's how it works:
You are driving on a city street at the legal speed limit. You approach an intersection for which you do NOT have a Stop. No traffic signal, no Stop sign, no Yield sign. But there is a Stop sign for all intersecting traffic. A driver seeking to get into your lane is partially Stopped or maybe rolling to a Stop or actually Stopped as he or she is required. Any driver should STOP but doesn't. Obnoxiously he or she inches into the intersection. Their intention is to cause you to slow down ever so slightly, ultimately to offer time to make a turn into your lane before you hear metal crunching. If your hesitation is sensed, they will inch forward a more, looking to cause more hesitation on your part. It is kind of like a Game of Chicken.
Some Boston drivers will actually force you to slow down regardless of the catastrophic possibilities. The worst part is that beyond the Other Guy's initial glance, no additional information would be required for that driver to turn into your lane.
To hesitate is to lose. To ignore is to intimidate.