I recently mentioned that Brazil’s estimated population was 210,147,125 in 2019. Much of that population is also densely concentrated in a few small areas. It’s a rough situation with respect to epidemics, and it’s always been that way in many of the countries very near the Equator in spite of more than a hundred years of efforts of many philanthropists. It appears that it has much to do with physical brain differences and other differences that make cultures difficult to change.
To say it is the result of brain differences, is theory until it is verified with real science. I say the most likely reason is the resistance to change is a factor of culture that is learned. Culture is passed down from generation to generation much like genetic inheritance. You can change culture but inherited characteristics can be impossible.