John Henryism is a strategy for coping with prolonged exposure to stresses such as social discrimination by expending high levels of effort which results in accumulating physiological costs.
The term was conceived by epidemiologist and public health researcher Sherman James while investigating racial health disparities. One of the people he interviewed was a black man who, despite being born into an impoverished sharecropper family and having only a second grade education, could read and write, had freed himself and his offspring from the sharecropper system, had 75 acres (300,000 m2) of farmed land by age 40, but by his 50s had hypertension, arthritis, and severe peptic ulcer disease. His name, John Henry Martin, and his circumstances are evocative of folk hero John Henry, an African American who worked vigorously enough to compete successfully with a steam powered machine, but died as a result of his effort.
Sherman James developed a scale for measuring John Henryism based on rating agreement with a series of statements such as "When things don't go the way I want them to, that just makes me work even harder." Men who score higher on this scale generally have higher blood pressure than men with lower scores. This effect is strongest in those who are poorest.