Biocultural belief and iodine prophylaxis.

Iodine prophylaxis, the most cost-effective public health intervention as yet known, has been slow to be adopted even where goiter and cretinism--the most common expressions of iodine deficiency disorders (IDD)--have long been known to be endemic and where underdevelopment cannot explain the absence of prophylaxis. Belief in the hereditary causation of IDD tends to be high in societies where familial goiter is common and endogamy is high. This belief props up opposition to prophylaxis, making dietary intervention appear both useless and wasteful. The examination of genealogies (pedigrees) alongside dietary history can erode support for hereditary causation. This can be done by charting the incidence of IDD against social and dietary changes.