Brachymesophalangia of digit five in ten populations

Brachymesophalangia, involving both reduction in length and increase in breadth of a middle segment was studied in the fifth digital ray in over 10,000 radiographs from ten countries. Population frequencies increase systematically from samples of European origin through to South American Indians and Asiatics. Lack of relationship between delayed appearance of ossification centers and brachymesophalangia of digit five in areas of protein‐calorie malnutrition indicates that nutritional delay is not a cause of brachymesophalangia though this trait, associated with size reduction of other digits and metacarpals, may be selectively advantageous where reduced body size is adaptive.