What do you think explains it?
Of course there is.
It would be truly astonishing if there wasn't.
Finding it might prove hard, though. And anyway, so what? If we did find those neural correlates and genetic components we'd... do what, exactly? Invent a pill, a therapy?
In the meantime, we can rationalise simply that xenophobia is destructive, and we can determine effective interventions.
Should we tackle what our understanding currently allows, rather than waiting to uncover an explanation?
If we go further fighting racism, what are those effective interventions? Can we even trust that current relatively good situation will continue? Is there any way to reliably export western anti-racism?
Alternatively we just accept the current levels. Maybe express disappointment on Facebook.
If this scapegoating phenomena is somehow built in feature of human beings, what/who would be the healthiest possible target for it?
If it's not built in feature, how can it be eradicated?
This is why I can't take the leftist arguments seriously. You refute phenomenon that have been taking place for thousands of years in order to glorify an ideology that you believe in without a single shred of evidence...
If you think that the fact that certain cities voted X compared to others who voted Y describes the sudden rise of nationalism across all of Europe AT THE SAME TIME, then you sir are in for a ride.
I didn't claim to be "leftist". I'm not "glorifying" anything. I'm not sure what you think I'm "refuting".
If by "refute phenomenon (sic) that have been taking place for thousands of years" you mean "racism" I'm not refuting the fact that it exists, what a strange claim that would be. I don't really follow what you're saying here at all.
I certainly didn't claim that Brexit voting patterns describe (do you mean explain?) the rise of pan-European nationalism. So again I don't follow what you're saying here.
In fact, I believe quite the reverse direction of influence: that the rise in pan-European nationalism influenced a vocal minority of the vote who now feel legitamised.
I suspect that the rise in pan-European nationalism is due to people being worried about recession, austerity, crumbling national institutions, etc etc. and immigration has become a surrogate for that: There's only so much cash in the coffers; there aren't enough {houses,schools,hospitals,whatever}; immigrants consume a non-zero fraction of these resources; therefore reducing the number of immigrants will improve the capacity of these services.
The problem being, of course, that you could pick any scapegoat and substitute it into that equation equally well. Consequently, when people do pick immigration as their scapegoat of choice, I consider that xenophobic.
The areas that voted leave seem to demonstrate xenophobia in its fundamental form: fear of the other.
Leave voters clearly are not all racist. Unfortunately, though, a vocal racist minority has taken the referendum result as validating their views.
Racism should absolutely be called out where it exists.
Your argument that homogeneity invoked a social survival instinct needs strong references, otherwise it sounds like hand-waving legitimising of xenophobia. We're smarter than that.