The theory was almost forgotten, but was revived by his student John L. Horn (1966) who later argued Gf and Gc were only two among several factors, and who eventually identified nine or ten broad abilities.
Teorien blev næsten glemt, men blev genoplivet af hans elev John L. Horn (1966), som senere argumenterede for at Gf og GC var kun to blandt flere faktorer, og han identificerende til sidst 9 eller 10 brede evner.