Physicians, parents and children are frequently interested in determining the relation of the size of a child to the normal. It may be recalled that there are at least three ways of doing this. As an example, the evaluation of the height of a child may be considered.
A first step is to estimate from the comparison of the heights of the parents with that of the average adult how much variation from the normal height should be accepted for the child. The defect in this method is that the law of heredity is not sufficiently understood to make such a prediction possible. The best method that can be proposed is a rough approximation based on the expectation that the stature of the child at maturity will be an average of the values for the parents. To use this method, the stature of the parent of the sex opposite that