Interesting comment. I'll say it another way: in America, people either agree or disagree with you. That's not my personal viewpoint but one that doesn't seem inconceivable to an outsider.

It's hard to generalize correctly about a population of three hundred million.

That's especially true when doing it based on personal experience.

I don't think the difference between a country of 125 million and 300 million is very meaningful in that regard.

I don't think it's easy to generalize about Japan's population either.

Hawaii is a place where that might be fairly said, though. Setting aside island natives, Hawaii attracts a lot of people. The reasons for wanting to visit and preceding life situations vary quite a bit. The result is you do meet a lot of characters, at least on the big island.

I bet Hawaiians working in tourism meet a lot more people than I do. Maybe as many as two hundred a day (granted, only for a few minutes at those volumes).

If you manage to do that five days a week for thirty years, you meet 1.4 million people, or 0.4% of the US population.

Obviously in most cases you'd have no idea about how smart most of these people are. You'd probably remember the ones who did especially dumb or especially smart things in the three minutes you interacted with them, which doesn't actually tell you much about how smart they are. It's even worse for that than a puzzle-trivia interview.

I think my point stands, even for a Hawaiian in tourism.

I don’t suppose there is any scenario in which you would give human observation credit. Regarding sufficient sample size, a person in that scenario would achieve it in weeks, or perhaps a year, assuming variance in types of visitors over the seasons.

There are tons of scenarios in which I think human observations are all that matters.

I think trying to generalize about populations on this scale from personal interactions is worse than pointless.

I have plenty of value for a reduced statement, one that acknowledges explicitly that the speaker can only legitimately talk about his experiences, not the US or Japanese populations as a whole.