Although formally recognized by Cattell, the distinction was foreshadowed by Charles Spearman who originally developed the theory of g and made a similar observation regarding the difference between eductive and reproductive mental ability.
Selvom formelt anerkendt af Cattell blev forskellen overskygget af Charles Spearman, som oprindelig udviklede teorien om g og lavede en tilsvarende observation om forskellen på intelligens via uddannelse og reproduktive mentale evner.