Educability-and-Group-Differences-1973-by-Arthur-Robert-Jensen

Multiple and Partial Correlation Methods 209
method simple, we will assume no correlation between genotypes
and environments, although a solution could be obtained by this
method if there were an independent estimate of the G x E
covariance. With this simplifying assumption of zero G x E
correlation, we can only underestimate the true proportion of
genetic variance or heritability, so, if anything, we err in favor
of environment.5 The total variance of tests 1 and 2 can be
represented as follows:
Test 1: cr2 = 0q + 01
and, since h\ = 0-5,
a2 = 0*5