He manifestly does not argue for 'superiority' or 'betterness', which is a value judgment (not objective).
I mean, he is calling our societies "WEIRD" (acronym and literal pun) -
highly individualistic, self-obsessed, guilt-ridden and analytical in thinking style versus kin-based societies that evidence
greater conformity, less individualism, more holistic thinking,
fewer guilty experiences.
As a human evolutionary biologist, he is concerned with understanding why this psychological variation appears to exist and in addition (a) Western societies have tended to be more "
educated, industrialized, rich, democratic" with and (b) account for the West's rapid intellectual, technological, economic and political progress from 1500.
It's not about one being 'superior' to another. The crux is actually his finding that the structure of our family networks play a central role in explaining global psychological diversity.
See:
‘The WEIRDest People in the World’: How cultural evolution changes the brain
The WEIRDest People in the World is not a book for neuroscientists or anthropologists. Its target audience is educated readers of all types. There is no doctrine or dogma, simply arguments based on sound research, including the author’s own. Henrich takes the reader by the hand through a complex reality – our species is complex – showing how a scientific approach led to his conclusions, however shocking they may be. It’s a refreshing approach in a nonfiction landscape littered with baseless opinions
A New Theory of Western Civilization
Henrich’s most consequential—and startling—claim is that WEIRD and non-WEIRD people possess opposing cognitive styles. They think differently. Standing apart from the community, primed to break wholes into parts and classify them, Westerners are more analytical. People from kinship-intensive cultures, by comparison, tend to think more holistically. They focus on relationships rather than categories. Henrich defends this sweeping thesis with several studies, including a test known as the Triad Task. Subjects are shown three images—say, a rabbit, a carrot, and a cat. The goal is to match a “target object”—the rabbit—with a second object. A person who matches the rabbit with the cat classifies: The rabbit and the cat are animals. A person who matches the rabbit with the carrot looks for relationships between the objects: The rabbit eats the carrot....
Henrich’s macro-cultural relativism has its virtues. It widens our field of vision as we assess Western values—such as objectivity, free speech, democracy, and the scientific method—that have come under sharp attack. The big-picture approach soars above the reigning paradigms in the study of European history, which have a way of collapsing into narratives of villains and victims. He refutes genetic theories of European superiority and makes a good case against economic determinism. His quarry are the “enlightened” Westerners—would-be democratizers, globalizers, well-intended purveyors of humanitarian aid—who impose impersonal institutions and abstract political principles on societies rooted in familial networks, and don’t seem to notice the trouble that follows.
... Who would have imagined that the Catholic Church would have spawned so many self-involved nonconformists? What else might our curious history yield? Henrich’s social-scientist stance of neutrality may also relieve Westerners of some (one hopes not all) of their burden of guilt. “By highlighting the peculiarities of WEIRD people, I’m not denigrating these populations or any others,” he writes. WEIRDos aren’t all bad; they’re provincial. Henrich offers a capacious new perspective that could facilitate the necessary work of sorting out what’s irredeemable and what’s invaluable in the singular, impressive, and wildly problematic legacy of Western domination.