Is it because they have cooties?

Why is the Reich Lab not acknowledging prior work by other researchers?

Theft of fire by Prometheus, Christian Griepenkerl (1878)

This past week, Nature published a paper on the evolution of Europeans over the past ten thousand years — a span of time that has transformed them in many aspects of mind and body:

… in the past ten millennia, we find that many hundreds of alleles have been a affected by strong directional selection. We also document one-standard-deviation changes on the scale of modern variation in combinations of alleles that today predict complex traits. This includes decreases in predicted body fat and schizophrenia, and increases in measures of cognitive performance. (Akbari et al., 2026)

After initial release as a preprint in September 2024, the paper remained in peer review for more than a year and a half — much longer than the usual four to six months, and a sign of its controversial nature.

Its findings certainly challenge the dominant view that genetic evolution has changed Homo sapiens only in minor ways, with the major changes being in the realm of culture. Consequently, most peer-reviewers assume that human populations differ genetically only in simple traits, and not in complex ones like cognitive ability.

This assumption has been challenged by a minority of geneticists and anthropologists, beginning in the 1980s with L.L. Cavalli-Sforza, Robert Boyd, Peter Richerson, and Pierre van den Berghe. Over the last two decades, their place has been taken by John Hawks, Greg Cochran, and Henry Harpending.

Their argument can be summarized as follows:

• Humans adapt to their cultural environment just as they adapt to their natural environment

• In both cases, the adaptations can be genetic

• Because humans adapt to a faster-changing cultural environment, and not just a slow-changing natural environment, they undergo more genetic change, not less. They create their environment, and it recreates them … through natural selection.

This can be seen in the timeline of changes to the human genome: new adaptive alleles were gained at a rate more than a hundred times higher when hunting and gathering gave way to farming, and this faster rate continued well into recorded history (Cochran & Harpending, 2009; Hawks et al., 2007).

During the time of the earliest farmers, humans had already adapted to the full range of natural environments from the equator to the arctic. They were now adapting to the innovations that farming made possible: new foods, sedentism, larger communities, and more interaction with non-kin. There then followed a cascade of further changes: the rise of the state, the rule of law, the development of trade, the growth of literacy and numeracy, and much more.

This cascade of changes created new demands on mind and body that varied from one culture to another. Demands on the mind especially increased. It now became necessary to process a greater volume of information from a greater number of sources in a greater variety of ways. Those who could meet such demands had an advantage over those who couldn’t.

Ancient DNA, a tool for charting cognitive evolution

DNA has been retrieved from human remains at many archaeological sites, particularly over the last two decades. Meanwhile, researchers have discovered thousands of alleles that affect IQ or educational attainment (Okbay et al., 2022). By identifying which of them are present in a population, we can estimate its average cognitive ability. This measure — the “cognitive polygenic score” — shows a 90% correlation with the mean IQ of the population (Piffer, 2019).

If we have enough DNA from each period of history and prehistory, we can chart how cognitive ability has evolved over time. This sort of evolution has been charted mostly for Europeans, since more DNA has been collected from them. Specifically, there have been four studies:

Woodley et al. (2017)

The authors used a dataset of 99 genomes dating from 4,560 to 1,210 years ago, as well as 503 modern genomes. The genomes were not only from Europe but also from Central Asia. The authors calculated three types of polygenic score, using alleles linked to educational attainment.

The results show an upward trend over the past four to five thousand years. Given the small size of the dataset, it was impossible to measure changes in the speed or direction of cognitive evolution during that time period.

Kuijpers et al. (2022)

The authors used a dataset of 827 genomes dating from over 11,000 years ago to under 5,000 years ago, as well as 250 modern genomes. They calculated three types of polygenic score, using alleles linked to intelligence, fluid intelligence, or educational attainment.

The results show:

• no change in cognitive ability during the long period of hunting and gathering

• a sustained upward trend from the advent of farming to the dawn of history

• stagnation during Roman times

• a renewed upward trend during the last few centuries.

Higher levels of cognitive ability were favored by “the strong increase in social complexity resulting from the Neolithic revolution and the process of urbanization and occupational specialization.”

Piffer & Kirkegaard (2024)

The authors used a dataset of 2,625 genomes dating from the past 35,000 years. They calculated three types of polygenic score, using alleles linked to intelligence or educational attainment.

The results show:

• no change in cognitive ability between 35,000 and 15,000 years ago

• an upward trend beginning near the end of the last ice age and lasting to the present.

The stagnation during Roman times, observed in the previous study, is probably obscured here by the large number of genomes from non-Romanized regions of Europe. When the authors examined data from central Italy alone, they found that cognitive ability stopped rising near the end of the Roman Republic and then fell throughout the Imperial Era (Piffer et al., 2023; see also Frost, 2023).

Akbari et al. (2026)

This is the latest and most prestigious study. It was carried out by the Reich Lab at Harvard Medical School, using a dataset of 15,836 genomes dating from the past 10,000 years. The authors calculated three types of polygenic score, using alleles linked to intelligence, household income, or years of schooling.

The results show:

• a surge in cognitive ability between 9,000 and 7,000 years ago among the earliest farmers

• a slower upward trend, with a possible decline between 2,000 and 1,000 years ago.

The initial surge may have been driven by strong selection for cognitive ability among the earliest farmers. Or the cause may have been assimilation of hunter-gatherers, particularly those from the cognitively demanding environments of northern Europe (Frost, 2019). The cause is difficult to pinpoint because we have only small numbers of European hunter-gatherer genomes from that time period, with even fewer from the north.

A replicated finding presented as a new one

At first sight, the four studies seem consistent with normal science. The first one produced a new finding, and the later ones replicated it with more data and better methodology.

However, the latest study does not acknowledge the three earlier ones. Look for yourself. All three are absent from the 220 references. The latest study is presented as an entirely novel work.

In a private reply to Davide Piffer, Ali Akbari explained that the Piffer and Kirkegaard paper was not cited because it “lacked proper calibration, did not adequately deal with inflation or multiple testing, and therefore did not count as relevant prior evidence for directional selection” (Piffer, 2026). If these concerns were as crucial as Akbari makes them out to be, the prior studies would not have been so strikingly similar in their results. Clearly, these studies had some value. Is Akbari denying that they motivated the Reich Lab to go ahead and do its own study?

Actually, there is a good reason for not acknowledging the prior studies. If they had been acknowledged, Nature might have rejected the paper and forced the Reich Lab to resubmit to a lesser journal. Keep in mind that Davide Piffer, Emil Kirkegaard, and Michael A. Woodley of Menie are personae non gratae in much of academia due to their work on IQ differences. The mere mention of their names might have antagonized the reviewers and tipped the balance toward rejection.

As things turned out, the paper barely got accepted. This may also explain why it was kept out of the media spotlight … until now. David Reich wanted any controversy to be after publication, and not during peer review.

Of course, by taking credit for this scientific discovery, he and his research team are embracing the very thing they were distancing themselves from. If mean IQ can differ from one time period to another within the same population, it probably also differs between populations. Why not? Time and space are two sides of the same coin.

Think that over. Differences in mean IQ across space are due to differing trajectories of mean IQ over time.

It’s not sporting and it sucks, but …

Let’s put personal vanity aside and see the big picture. The Reich Lab paper has the potential to settle the “race and IQ” issue — first, by opening up debate and, second, by showing that IQ differences are frequent, expectable, and even ubiquitous.

Mean IQ can differ between populations that no one would consider to be “races.” It can differ even between two time periods of the same population. Such ubiquity arises because natural selection acts on cognitive ability in a multitude of ways and for a multitude of reasons.

All of this seems obvious to me and is likely obvious to Ali Akbari and David Reich. But it is far from obvious to most people, including many proponents of cancel culture. For this, we should be thankful.

References

Akbari, A., Perry, A., Barton, A.R. et al. (2026). Ancient DNA reveals pervasive directional selection across West Eurasia. Nature (2026). https://doi.org/10.1038/s41586-026-10358-1

Cochran, G. & Harpending, H. (2009). The 10,000 Year Explosion: How Civilization Accelerated Human Evolution. Basic Books: New York. https://www.amazon.com/000-Year-Explosion-Civilization-Accelerated/dp/0465020429

Frost, P. (2019). The Original Industrial Revolution. Did Cold Winters Select for Cognitive Ability? Psych, 1(1), 166-181. https://doi.org/10.3390/psych1010012

Frost, P. (2023). Was the Roman Empire eugenic? Peter Frost’s Newsletter, December 11.

Hawks, J., Wang, E. T., Cochran, G. M., Harpending, H. C., & Moyzis, R. K. (2007). Recent acceleration of human adaptive evolution. Proceedings of the National Academy of Sciences (USA), 104, 20753-20758. https://doi.org/10.1073/pnas.0707650104

Kuijpers, Y., Domínguez-Andrés, J., Bakker, O.B., Gupta, M.K., Grasshoff, M., Xu, C.J., Joosten, L.A.B., Bertranpetit, J., Netea, M.G., & Li, Y. (2022). Evolutionary Trajectories of Complex Traits in European Populations of Modern Humans. Frontiers in Genetics, 13, 833190. https://doi.org/10.3389/fgene.2022.833190

Okbay, A., Wu, Y., Wang, N., Jayashankar, H., Bennett, M., Nehzati, S.M., Sidorenko, J., Kweon, H., Goldman, G., Gjorgjieva, T., Jiang, Y., Hicks, B., Tian, C., Hinds, D.A., Ahlskog, R., Magnusson, P.K.E., Oskarsson, S., Hayward, C., Campbell, A., Porteous, D.J., … Young, A. I. (2022). Polygenic prediction of educational attainment within and between families from genome-wide association analyses in 3 million individuals. Nature Genetics, 54, 437–449. https://doi.org/10.1038/s41588-022-01016-z

Piffer, D. (2019). Evidence for Recent Polygenic Selection on Educational Attainment and Intelligence Inferred from Gwas Hits: A Replication of Previous Findings Using Recent Data. Psych, 1(1), 55-75. https://doi.org/10.3390/psych1010005

Piffer, D. (2026). What Akbari’s Reply Gets Wrong About Science. PifferPilfer, April 16.

Piffer D, Dutton, E., & Kirkegaard, E.O.W. (2023). Intelligence Trends in Ancient Rome: The Rise and Fall of Roman Polygenic Scores. OpenPsych. Published online July 21, 2023. https://doi.org/10.26775/OP.2023.07.21

Piffer, D., & Kirkegaard, E. O. (2024). Evolutionary trends of polygenic scores in European populations from the Paleolithic to modern times. Twin Research and Human Genetics, 27(1), 30-49. https://doi.org/10.1017/thg.2024.8

Woodley, M. A., Younuskunju, S., Balan, B., & Piffer, D. (2017). Holocene selection for variants associated with general cognitive ability: Comparing ancient and modern genomes. Twin Research and Human Genetics, 20(4), 271-280. https://doi.org/10.1017/thg.2017.37