^ — 3 — ? 



GRADES OF PARENTS 



GRADES OF PARENTS 



Figure 2, A 



Fig. 2, A, B, C Regression straight lines and empirical means calculated 

 from the data in table 1, formulae in table 2. Each dot represents the mean of 

 the sons or daughter that were produced by parents of the grade indicated on 

 the scale at the bottom of the figure. One bristle is the unit of the scale of 

 means. Since the scales of means for different generations overlap, the absolute 

 values of the empirical means cannot be given on the scales. 



429 



