Migration raised medieval height and blond‑hair scores

Ancient‑DNA polygenic scoring shows early medieval (c. 450–799 CE) English burials average substantially higher genetic scores for height and for blond hair than Iron‑Age samples, consistent with influx from North‑Sea associated groups and later admixture reducing those means in later medieval samples. The result is an empirically testable claim based on named datasets and reference panels rather than a vague historical narrative. — If robust, this finding reframes discussions about how demographic turnovers affect genetic predispositions for visible physical traits and forces careful public discussion about methods, reference choices and limits when discussing ancestry and cognitive traits.