Selfishness in America has also a moronic side

https://pacheco-torgal.blogspot.com/2020/07/american-selfishness-both-in-use-of.html

But what is hard to understand is why black people one of the risk groups has the lowest percentage of Yes answers !!!
https://www.sciencemag.org/news/2020/06/just-50-americans-plan-get-covid-19-vaccine-here-s-how-win-over-rest