Here’s a little experiment. Take a second to think about how you would fill in the blank in this sentence: “I am _____.”

If you’re anything like me, the first descriptors that come to mind are personal attributes (like “curious” or “kind”) or identities (like “a journalist” or “a runner”). And if you answered that way, then I have some news for you: You are weird.

I mean that in a very specific way. In social science, WEIRD is an acronym that stands for Western, Educated, Industrialized, Rich and Democratic. Most societies in the world today — and throughout human history — don’t fit that description. And when people from non-WEIRD cultures answer the “I am” statement, they tend to give very different answers, defining themselves with relation-based descriptors like “Moe’s father” or “David’s brother.”

That difference is only the tip of the iceberg. Much of what we take for granted as basic elements of human psychology and ethics are actually a peculiar WEIRD way of viewing the world.

Joseph Henrich, an anthropologist at Harvard University, believes that this distinction between WEIRD and non-WEIRD psychologies is absolutely central to understanding our modern world. His 2020 book, “The WEIRDest People in the World: How the West Became Psychologically Peculiar and Particularly Prosperous,” explores the origins of these differences and argues that the emergence of a distinctly WEIRD psychology was central to the development of everything from the Industrial Revolution and market economies to representative government and human rights.

We discuss Henrich’s theory of how “cultural evolution” leads to psychological — even genetic — changes in humans, the difference between societies that experience “shame” as a dominant emotion as opposed to “guilt,” the unique power of religion in driving cultural change, how cultural inventions like reading have literally reshaped human biology, why religious communes tend to outlast secular ones, why Henrich believes there is no static “human nature” aside from our cultural learning abilities, how differences in moral psychology across the United States can predict Donald Trump’s 2016 and 2020 vote share, why higher levels of immigration tend to lead to far more innovation and more.

Book recommendations:

Why Europe? by Michael Mitterauer

Guns, Germs, and Steel by Jared Diamond

The Chosen Few by Maristella Botticini and Zvi Eckstein

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You can find transcripts (posted midday) and more episodes of “The Ezra Klein Show” at nytimes.com/ezra-klein-podcast, and you can find Ezra on Twitter @ezraklein. Book recommendations from all our guests are listed at https://www.nytimes.com/article/ezra-klein-show-book-recs.

This episode of “The Ezra Klein Show” was produced by Roge Karma. Fact-checking by Michelle Harris, Mary Marge Locker and Kate Sinclair. Mixing by Sonia Herrero. Our production team is Emefa Agawu, Annie Galvin, Jeff Geld and Kristin Lin. Original music by Isaac Jones. Audience strategy by Shannon Busta. The executive producer of New York Times Opinion Audio is Annie-Rose Strasser. Special thanks to Kristina Samulewski.

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