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Findings from 100 studies, all based on measures for the same variable obtained since 1950, are assembled and compared. The childhood period encompassed is from age 6 years to age 10 years, and the variable dealt with is thickness of a mid­posterior brachial fold of skin and subcutaneous adipose tissue over the triceps muscle. Major focus is on comparison of averages for boys and girls of different ethnic groups. Background for interpreting and evaluating variations among sample averages is provided by examining differences between the arithmetic mean and median from large samples, and using variability statistics from large samples to obtain estimates of population standard deviation suitable for rigorous testing of significance hypotheses. At age 6 years, averages for different ethnic groups vary from less than 5.0 mm to 10.0 mm on boys, and from less than 6.0 mm to 12.0 mm on girls. Low values characterize Arab rural groups in Egypt, Turkana rural groups in Kenya, and Ibo rural groups in Nigeria: high values represent New Zealand Maori children, and White children in Australia, Europe, New Zealand, and the United States. Typically, averages for girls are found to exceed those for boys by 1.2 mm at age 6 years, 1.5 mm at age 8 years, and 1.8 mm at age 10 years. Comparisons are made for socioeconomic, nutritional, rural-urban, and osseous subgroups.