Default “discrimination” seems hard-wired in — an evolutionary trait borne of groups doing better in the wild outdoors, and at a lizard-brain level triggered by physical appearance.
It’s the “all x are bad drivers” notion we can have because, when we experience a notable incident in traffic we look to see if there’s some defining characteristic to said threat; if there’s nothing we clock as “different” then we don’t make a note of the physical characteristics, and go about our day, but if there is, we might log the incident and complain about it later.
Particularly in the USA (I’m Australian, by the way) there seems to be a notable cultural divide between “white” and “not-white” — perhaps engendered historically by years of segregation, both legally and culturally enforced. This can enforce the feeling of “other” (both ways), and you get your gut, limbic response to someone with a certain set of physical traits.
So yeah; I think that as long as there are groups of people with distinct phenotypes then there will be a tendency for people to make unreasoned judgements about “those people”. In that homogenous brown-skinned human race of the future, they will probably discriminate against people with slightly smaller-than-average hands.
Just look at that freakishly small-handed Trump guy ..