There is a wonderful expression in Japanese: Fūdo ni nareru, which means something like "to become acclimatized to natural conditions."
The kanji characters making up "fūdo" are fū (wind) and do (earth), and the expression tends to refer to how Japan's natural conditions — its day-to-day weather and overall climate — influence the character of its people.
I like to think that most people, Japanese included, are quite flexible, and will adapt well to new conditions — in other words, they acclimatize. If "fūdo ni nareru" is correct, this means their innate character will change too, over time.