It 'would be difficult to test psychology I'd think,
As I agree with you, on what a large role factors other than genetics, can play.
Also criteria of what was being tested.
I 'imagine, that geographic populations behaviors, often vary widely throughout their histories,
As in even 'one geographic population, I mean, varies throughout it's history,
Based on it's environment,
Society, technology, weather, competition, wildlife, other, all being environment.
@Self
Reasonable test?
Though one might argue if they were carefully tested every generation, better data could be had on locations,
Still, maybe would need 'all geographic populations to use the same test, for their data to be good to compare?
. . .
Unreasonable test,
Random remove half population, every generation,
Separate on geographic population,
Place in similar starting environments,
Of which there would have to be multiple for each geographic population, (Criteria of what was being tested)
. . .