The Use of Correlation and Regression in the Analysis of Family Resemblance

The use of correlation and regression as applied to the analysis of family resemblance is discussed. The application of these statistical techniques to family data is not routine because the number of siblings per family is in general variable. Topics dealt with include estimation of sib-sib (intraclass) correlation, parent-child (interclass) correlation and regression of child on parent. An example is given.