Data◆Audio · 15:45 — 17:15
Selection on the genetic predictors of cognitive/IQ-test performance peaked between roughly 5,000 and 2,000 years ago during the Bronze Age, with almost no detectable selection on this trait in the last 2,000 years.
Reich's team found that selection intensity on the genetic predictor of IQ-test performance spiked sharply between 4,000 and 2,000 years ago, pushing the trait up by roughly a standard deviation, while the last 2,000 years show essentially no selection on it at all. ✦ AI generated
David Reich · Dwarkesh Podcast · 2026-05-08 · original ↗
plays this moment only · 15:45 — 17:15
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“So what’s going on? Why is the Bronze Age so special across all these different traits that you’re observing?”
What you see when you look at intelligence is that this maxes out in the Bronze Age, between 5,000 and 2,000 years ago. The impact in the last 2,000 years is almost nothing. There’s no evidence of natural selection at all.
verbatim transcript · starts at 15:45
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15:45– Natural selection intensified during the Bronze Age
15:45– Natural selection intensified during the Bronze Age
- ·Selection intensity spiked 4,000–2,000 years ago
- ·Trait rose roughly one standard deviation
- ·Almost no selection in last 2,000 years
- ·No evidence of natural selection today
- ·Bronze Age spike: ~5,000–2,000 years ago
- ·Last 2,000 years: essentially no selection
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