observations I've made so far, with a sample size of over 1000:
most, but not all, ethnically slavic people are able to slav squat.
most balkan people are also able to
any slavic and balkan people who can't slav squat are ashamed at the fact
the ethnicity with the highest ability to slav squat seems to be ashkenazi jews, with many responding and only 1 or 2 being unable to
people are confusing the slav squat with the asian squat - afaik, the slav squat has a wider stance, with your knees pointed outwards. the asian squat is narrower stance, with your knees tucked under your chin
nevertheless, most east and southeast asian people seem to be able to do both, and were astonished that other people find it hard
most americans don't seem to know what an ethnicity is, with lots of them just responding 'american' or 'white' (one of those is a nationality, the other is a race)
most european americans cannot slav squat, but those who could almost universally answered that they are largely ethnically slavic
the numbers were around 50% for native american respondees, though lots of european americans seemed to claim they have native friends who can
a lot more people in the world have ehlers danlos syndrome (hEDS) than I would have imagined (I have it too)
a lot of people in the notes claimed that the ability to slav squat came from flexibility in childhood, which is an interesting theory. however, I have serious issues with the external rotator cuff on my hip, and I can still do it easily
very few southern europeans or arabs answered, so numbers still inconclusive there
south americans (people with mixed indigenous and iberian heritage) seem to be able to do it more often than not
the numbers are around 50% for ethnically british and irish people
bonus observation: one american described their ethnicity as 'catholic', and another as 'anglo-saxon' which is the funniest thing I've ever fucking read