Seriously.
I believe from my 83 years of life that -- generally speaking -- Caucasians are the easiest to get along with. Since -- until recently -- they have been the vast majority, they seem to have the fewest hang ups. That is not to say, however, that there are not a lot of Caucasian jackasses -- or worse.
I have found that Asians really do differ. For example, the Chinese and the Japanese and the Koreans and the Vietnamese do have particular personalities. Personally, I find the Chinese the easiest to get along with. One thing in common: I never fear physical violence from any of them.
I find Latinxs the most friendly. I have found there's a big difference between the Latinxs born here and the ones who are immigrants. The former have hang ups that the latter do not. That is, to say the former have met prejudice and discrimination that the latter have not, since the latter are new to the country. I get along with both so long as I am respectful and careful.
Last but not least, I find the most difficult to get along with are African Americans. The older ones (in thirties and beyond) are usually pretty nice. In general, they often seem to be more tolerant when it comes to social behavior than the other ethnicities. I have had, however, quite a few unpleasant experiences with African American teenagers and twentysomethings -- dating back to the 1960s. I admit that I am very wary of them. And the media stories about their sucker punchings do nothing to alleviate my feelings. I always make certain to show respect to them, for they are very touchy about being disrespected.
Wow! What a strange country. It is a miracle that we all get along as well as we do!