Henrich had thought he would be adding a small branch to an established tree of knowledge. It turned out he was sawing at the very trunk.
At the heart of most of that research was the implicit assumption that the results revealed evolved psychological traits common to all humans, never mind that the test subjects were nearly always from the industrialized West. Henrich realized that if the Machiguenga results stood up, and if similar differences could be measured across other populations, this assumption of universality would have to be challenged.
Why Americans Are the Weirdest People in the World