Reuters reports,

Karl Marx, who complained of excruciating boils, actually suffered from a chronic skin disease with known psychological effects that may well have influenced his writings, a British expert said on Tuesday.

…hidradenitis greatly reduced his self-esteem,” said Shuster, who published his findings in the British Journal of Dermatology.

…Shuster based his diagnosis on an analysis of Marx’s extensive correspondence, in which he wrote to friends about his health and described his skin lesions as “curs” and “swine.”

“The bourgeoisie will remember my carbuncles until their dying day,” Marx told Friedrich Engels in a letter from 1867.

I would love to see studies of the effect of temperament on beliefs. Of course, that would require getting reliable measurements of temperament. Since I don’t accept self-reporting surveys–I’m talking about you, happiness research–I’m not sure how to go about it.

Thanks to Michael C. Moynihan of the Reason blog for the pointer.

UPDATE: some interesting reader comments, including a pointer to this interesting post. A brief excerpt:

There is some evidence that people become political liberals because they perceive the government to be an extension of their parents. That’s why college-age people tend to be more liberal than older people. For young people, who cannot yet survive well on their own, the dependence on parents and their financial resources is still strong. Yearning for a paternalistic government in many ways represents a transference of parental dependency onto a strong, Contrary to popular belief, political conservatism may actually be a measure of a person’s willingness to take personal risks–to go without a net, so to speak. Liberals, in contrast, look to a strong central government as a source of guidance and financial security. all-embracing central authority that provides guidance and minimizes risk. The ideal government for liberals is one that takes care of people’s financial and health-care needs at the expense of individual freedom, just as a parent would do.