New study links Neanderthal DNA to autism spectrum traits

Recent research has uncovered intriguing connections between Neanderthal genetic variants and autism spectrum disorder (ASD), shedding new light on the ancient roots of neurodiversity, Caliber.Az reports, citing earth.com.

About 50,000-60,000 years ago, early modern humans migrating out of Africa encountered Neanderthals in Eurasia, exchanging not only tools but also genes through interbreeding. It is estimated that Eurasian-derived populations carry approximately 2% Neanderthal DNA, acquired during these introgression events. Subsequent migrations back into Africa introduced smaller amounts of Neanderthal ancestry across the continent. Today, nearly everyone on Earth carries at least a trace of Neanderthal heritage, though the amount varies.

While many Neanderthal genetic fragments have been lost due to natural selection—especially those affecting brain function—some variants remain in regions linked to perception, memory, and social cognition. A new study led by researchers from Clemson University and Loyola University investigated whether these lingering archaic DNA segments could influence autism.

The study compared whole-genome data from autistic individuals, their unaffected siblings, and unrelated controls across diverse ethnic backgrounds. The researchers found that “both rare and common Neanderthal-derived variants appeared more often in autistic participants.” Crucially, it was not the overall amount of Neanderthal DNA, but “possessing particular snippets” that correlated with ASD.

One notable pattern involved genes regulating communication between distant brain regions. Visual-processing circuits showed heightened activity, while the “default mode network, linked to daydreaming and social reflection, ran cooler.” These brain connectivity patterns align with traits commonly reported by autistic individuals, such as sharp pattern recognition paired with social fatigue.

Functional MRI scans from the same study confirmed that people carrying higher loads of these Neanderthal variants—autistic or not—exhibited stronger signaling in visual areas, while pathways associated with idle thought remained quieter. This suggests that “these ancient genes might sculpt a cognitive profile tuned for intense observation and precise motor planning.”

Archaeologists have noted similar cognitive strengths in Neanderthal craftsmanship. Their sophisticated Levallois technique for stone tool making required “stepwise planning, spatial reasoning, and sustained focus”—skills that resonate with those displayed by many autistic thinkers today.

The researchers propose an evolutionary explanation for the persistence of these variants: Neanderthals likely lived in small, close-knit groups where “visual scouting for game, shelter, or stone resources could outweigh complex social juggling.” When Homo sapiens interbred with them, these perceptual talents may have been advantageous enough to persist.

The study emphasizes that it “does not argue that Neanderthal DNA ‘causes’ autism.” Rather, it suggests that a handful of inherited genetic tweaks “can raise the odds of certain traits emerging along a spectrum.” Such traits may have provided benefits in ancestral environments—and continue to do so in areas valuing logic, detail, and pattern spotting.

Researchers also highlight that genetics is only one part of the autism puzzle, with environment and other genes playing crucial roles. Nonetheless, identifying Neanderthal contributions “helps explain why autism exists worldwide, independent of culture or upbringing,” and “reframes neurodiversity as a legacy of humanity’s mixed heritage rather than a modern anomaly.”

The study notes that “many families notice clusters of analytical talent—mathematicians, engineers, visual artists—scattered among autistic and non-autistic relatives alike.” The new findings provide a biological thread connecting these shared abilities.

Looking ahead, the research team hopes their work “will lead to further investigation into the ongoing influences of ancient hybridization between Homo sapiens and Neanderthals in brain development, human intelligence, and overall human health, as well as spur work into additional clinical resources for this complex population.”

Future projects aim to explore how Neanderthal variants affect other neurodevelopmental conditions, interact with modern lifestyles, and inform personalized support strategies.

Ultimately, this research underscores that human evolution did not end with one lineage replacing another. Instead, it wove together strengths from multiple ancestors, leaving genetic fingerprints that continue to shape human cognition, perception, and innovation today.

By Vugar Khalilov