Comparison of variance within and between sibships in anthropometric traits of mexican migrant and sedente families

Variance between and within sibships in anthropometric traits was ascertained in a sample of Mexican families in the U.S.A. (migrants) and in Mexico (sedentes), by sex. The factor of age was eliminated by standardization. The siblings intraclass coefficient of correlation for the various traits by means of the one-way variance analysis manifested differences between the sexes in various anthropometric traits. Variance between sibships was found to be significantly higher than within sibships in all the traits in each sex, and both migrant and sedente sibships. This result, also noted in other groups, would seem to reflect a general population phenomenon.