Consider each of the following relationships: the heights of fathers and the heights of their adults sons, the heights of husbands and the heights of their wives, and the heights of women at age 4 and their heights at age 18. Rank the correlation between these pairs of variables from largest to smallest. Explain your reasoning

We would expect the height of women at age 4 and their height as women at age 18 to be the highest correlation since it is rational to think taller children to turn out to be taller adults and shorter children to become shorter adults. The next highest would be the correlation between the father and their adult sons. Tall fathers be likely to have tall sons, but naturally not as tall, and similarly for shorter fathers. The lowest correlation would be between husbands and their wives. Husbands may be taller than their wives in common, but there is no purpose to expect anything more than a weak positive correlation.