and a distant cousin. Third, because density measures are ratio/proportion scores, they control for inflation of scores due to variation in subjects’ total number of alcohol-affected relatives. The benefit of using ratio scores, compared to the dichotomous measures which are nominal scores, is that they allow for a maximum potential score to always remain the same (i.e., 1) for all. Moreover, the algorithm used to generate the density measures counts the number of affected relatives and keeps the total weights of known relatives (denominator of the ratio score) constant (see supplementary material). Therefore, even if the affectedness status of a relative were to be unknown, it does not contribute to the density score whatsoever.
