The Correlation Between a Factor and a Measure

Piano playing equals age plus weekly hours of practice. Weight equals age plus ice cream consumption. You can see that there will be regression to the mean when we predict piano playing from weight, or vice versa. Any factor that influences one measure also influences the other. 100 % of determinants are shared. The correlation between self reported height and weight among adult american males is point four one. It took francis galton several years to figure out that correlation and regression are not two concepts but different perspectives on the same concept.