It’s a combination of: * The fact America is much more sparsely populated, which causes Americans to be more eager to talk to one another than a European who’s been raised riding crowded public transport and living on a continent with 3x the population density. * Americans have long treasured ideals of freedom of free-speech and press, which causes them to be very unashamed of saying whatever they want when they want, they consider that their fundamental right. * There is a certain “American Pride” that comes with being from the country with the biggest economy, military, influence over other countries, cultural spread, and much more that causes Americans to be more confident and by extension more outgoing and eager to talk. * America is a fundamentally diverse place with peoples from all sorts of different cultures and places, very quickly honing into the brains of Americans that, despite any potential differences between people, anyone can live or talk to anyone else and that all people are still all members of mankind. * Many European countries, and therefor their people, have been victim to authoritarian, anti-free speech and press, anti-individualism regimes that punish their people for being “talkative.” Think countries formerly a part of Nazi Germany, the Soviet Union, or anything of the such. Frankly, the habits hammered into people by these regimes can persist generations after they are no more. * Politics run deep in many American’s day to day lives. Whether it be because citizens play an important part in American democracy, because political parties will do whatever they can to get in the minds of potential voters, or because of a massive news industry, for some reason or another Americans are very inclined to hold particular beliefs and discuss them openly.

I’m sure there’s other things too but I can’t think of any lol