Social class, skin color, and arterial blood pressure in two societies.

Black people have higher blood pressure relative to whites; darker-skinned black people have higher blood pressure relative to lighter-skinned black people in some studies. These findings have been attributed either to racial-genetic factors or to sociocultural factors associated with social class. It is argued here that conventional social class theory is inadequate for the development of testable research hypotheses regarding skin color and blood pressure. New developments in social class theory are used to generate an alternate hypothesis. It is suggested that darker skin color is related to higher blood pressure in combination with the struggle to establish and maintain a middle-class life-style. Darker-skinned persons' claims to this social status are rejected in social interaction because of the use of skin color as a criterion of low social class in color-conscious societies. This hypothesis accounts for black-white differences in blood pressure in Brazil and for the association of darker skin color and blood pressure in a black American community in the United States. These results are consistent with a model in which skin color and blood pressure are associated solely through sociocultural processes.