Maximum likelihood estimation of components of variance and correlations in the analysis of family data

A simple iterative method is developed for computing the maximum likelihood estimates of the components of variance and thereby the intraclass and interclass correlations, under multivariate normal assumptions involving two classes. The method works efficiently for both balanced and unbalanced data and can be readily extended to situations involving three or more classes. It is particularly suitable for application to studies of quantitative variables in genetics and is illustrated by using some dermatoglyphic data.