For much of modern history, being left-handed wasn’t just considered unusual — it was treated as a problem to be fixed. Well into the 20th century, teachers in Britain, North America, and elsewhere routinely forced left-handed children to learn to write with their right hands. Some tied a child’s left hand behind their back or otherwise restrained it, believing they were helping the student develop “normally” and correctly.

Strange as it seems today, the idea had deep roots. The right hand had been associated with goodness, skill, and divine favor since antiquity, while the left became linked with weakness and bad luck. The English word “sinister” ultimately comes from the Latin word for “left,” a reminder of just how enduring those cultural attitudes became.

In the late 1800s, some researchers tried to dress those old prejudices in scientific clothing. Italian criminologist Cesare Lombroso claimed left-handedness was more frequently found among “women, children, and savages” — reflecting the racist, sexist, and colonial thinking of his era. He even published statistics that he believed proved left-handedness was linked to criminal behavior, though his methods and conclusions have long since been discredited. Nevertheless, his work helped reinforce the belief that left-handed children should be retrained.

Fortunately, psychologists and educators increasingly argued that forcing children to switch hands could do more harm than good. Those voices grew louder as the 20th century progressed, although it was not entirely unusual to find retraining efforts even in the 1980s. Today, scientists recognize handedness (the preference for a specific hand) as a normal part of human variation, influenced by a complex mix of genetics and development.