Farmer Brains, Hunter Brawns, Brown Skin? The Genetic Secrets of Ancient Conquerors

How ancient DNA and modern genetics are revealing the biological foundations of prehistory's most influential expansion

Around 5,300 years ago, a group of nomadic herders burst out of the grasslands north of the Black Sea and changed the world forever. The Yamnaya culture didn’t just migrate—they conquered, spreading their genes, their language, and their way of life across an area spanning from Western Europe to the steppes of Central Asia. Today, up to 50% of European ancestry traces back to these ancient pastoralists, and their linguistic legacy gave birth to the Indo-European language family that dominates from Ireland to India.

But what made the Yamnaya so remarkably successful? Was it just superior technology, favorable climate, or strategic timing? Or could there have been something in their very DNA that gave them an edge?

Unlocking Ancient Genetics

My new study (Piffer, 2025) has applied cutting-edge genetic analysis to this age-old question, using DNA from 414 ancient Eurasian individuals (Lazaridis et al., 2025; Nikitin et al., 2025) to calculate "polygenic scores"—essentially genetic scores that predict traits like intelligence, height, and psychological characteristics. By comparing these scores across different ancient populations, researchers have uncovered fascinating patterns that may help explain the Yamnaya’s unprecedented expansion.

The results paint a picture of a people who weren’t just culturally innovative but genetically poised to take advantage of their moment in history—somewhere between the brains of settled farmers and the brute strength of hunter-gatherers.

Farmer Brains, Hunter Brawns

While the Yamnaya descended from Mesolithic hunter-gatherers, they were noticeably more cognitively advanced than their ancestors. Genetic scores linked to educational attainment—a proxy for cognitive ability—were substantially higher in Yamnaya individuals than in the hunter-gatherers who came before them. This leap in brainpower likely reflected their more complex lifestyle: managing livestock, navigating open terrain, organizing mobile communities, and coordinating long-distance movements.

However, they still lagged behind the early Anatolian farmers, who had settled agricultural lifestyles, built permanent settlements, and likely developed more formalized systems of knowledge. The Yamnaya may not have matched these farmers in raw intellect, but they brought something else to the table—a powerful combination of improved intelligence, physical dominance, and adaptability.

The Genetic Advantage

My study found that Steppe Pastoralist ancestry—the genetic hallmark of the Yamnaya and their kin—was linked to elevated polygenic scores for educational attainment, even after accounting for geography and time. This suggests that the Yamnaya possessed a real biological advantage when it came to cognitive traits related to problem-solving and learning.

This cognitive step up from hunter-gatherers could have been pivotal. While farmers had the “brains,” they lacked the height and hardiness of the Yamnaya. The herders, by contrast, retained the brawn of their hunter ancestors while boosting their mental capacities just enough to dominate more sedentary populations. It was a rare and powerful mix.

We can compare the mean EA with that of other populations. The results show that the Yamnaya had higher EA than Copper Age cultures from the Volga region such as the Khvalynsk or their immediate pastoralist predecessors associated with the Serednii culture:

Height and Hardiness