the middle diagonal band running between the lower left and the upper right corners are either one high and one low, or both are medium ; they will produce Successes of Grade II. The three in and about the right-hand corner are either one medium with one low, or both are low ; they will produce Successes of Grade III. This is still more clearly seen by sorting the results into Table II., from which it is clear that a high grade of Success is statistically associated with a high, but less, grade of Ability, a medium with a medium, and a low
TABLE II.-ABILITY INDEPENDENT OF ENVIRONMENT.
Grades of Success.
I. II. III.
AE AG CG
AF BF BG
BE CE CF
2 of A i of A
i of B i of B i of B
r of C 2 of C
grade of Success with a low, but less low, grade of Ability.
Secondly, suppose A, B, C to be correlated with E, F, G, so that A is more likely to be associated with E than it is with F, and much more likely than with G. Similarly, C is most likely to be associated with G, less likely with F., and least likely with E. The general effect of these preferences will be well represented by divorcing the couples which differ by two grades-namely, AG and CE, by re-mating their constituents as AE and CG, and by re-sorting