The history and evolution of the labor insult

The term "scab" remains a potent insult within the American labor movement, used to shame individuals who cross picket lines, break up strikes, or refuse union membership. The term is intended to cast those who prioritize personal interest over class solidarity as traitors.

The word's origins trace back to Medieval Europe, where diseased skin was associated with immoral character. In the 19th-century United States, it became a common epithet used in union pamphlets and newspapers to chastise workers or leaders who cooperated with management. Other historical labor insults include "blackleg," "stool pigeon," and "fink"—the latter potentially derived from the Pinkerton detective agency.

Recent political tensions have also seen the term used outside traditional labor contexts; for instance, United Auto Workers President Shawn Fain called former president Donald Trump a "scab" in August 2024.