I often suspect that 'tribalism', in its many manifestations, is very close to being coded in our DNA, leading us to favor those who look like us and talk like us. Then I notice that very young children seem to be able to play with each other, taking almost no notice of their differences. Then I notice that as they approach adolescence, some children develop animosities toward some others, manifesting in bullying and social ostracism and elite'ism'.

Some of the changes are no doubt acquired from their 'tribe' (family, income group, language group,...etc..) but some seems to just well up from within as common conflicts are resolved by resorting to simplistic categorization. "He pushed me, and he looks 'different', therefore..." or even "She always gets better grades, and she's prettier than me, therefore..." (these are seldom expressed clearly & formally, but just in subconscious attitudes.)
So... what is 'coded' in our DNA may be a general tendency to react to conflicts quickly in some way that promotes 'us' and defines 'others' as flawed or enemies. Books have been written trying to sort this out.

So? Some people do NOT seem to operate this way and generally treat others as *human* first, rather than some arbitrary sub-category...until.... "those soft southern bastards " or "those idiots who support Manchester" or "anyone the same color as the one who stole my sandwich".
One of the hardest things in the Universe is to rationally and neutrally interact with people without an 'ism' creeping in, however subtly. How to overcome that? It is tempting to say simply 'education' - learning about others and studying history to become aware OF the thousand ways in which prejudice and selfishness color our humanity..... but we see some of the best 'educated' in society behave in some of the worst ways. It is not even simple 'intelligence' (as distinct from 'educated'), though both are fairly important to the process of overcoming *ism.

I will ask you (all of you) to think carefully and see if you can say that you have ever known anyone who truly exemplifies all the best qualities of lack of prejudice, fairness, honesty... and the attempt to use *reason* (" being an indian is not a factor in all poachers being assholes."") to deal with situations.
Then, the hardest trick.... do as one of my college professors tried to suggest as a 'goal'... run around behind yourself and observe yourself objectively! *I* can't really do it... but that concept is my goal, and is the closest I can come to recognizing my own tending toward some awkward *ism.

And 16 years of posting here at Mudcat and seriously thinking about all this has done as much as anything to get me a little ways toward that elusive goal.