Using the same experimental design of a sample of conventionally unrelated individuals, the experimenter can increase power by increasing sample size. Fortunately, power increases quadratically with sample size because every new sample is contrasted with all existing samples. The sampling variance of the estimate of the genetic correlation is generally much larger than that of the proportion of variance explained from a univariate analysis, consistent with the theory of the sampling variance of genetic correlations in pedigree designs [33].
