General Ability, Its Existence and Nature

General Ability' form ' and ' content ' ; by form is meant the kind of mental operation, as discrimination, observation, inference, etc. ; while the ' content denotes the different sorts of data, as colour, shape, number, etc., submitted to such operations].Among the upholders of the other side, Binet quotes one of US.Here, the view supported is that all performances depend to a certain degree upon one and the same general common factor, provisionally termed ' General Ability.' Correlations are thus produced between all sorts of performances, the amount of correlation being simply proportional to the extent that the performances concerned involve tlie use of this general common factor, or ' General Ability.'To these two extreme views cited by Binet may be added a great number of intermediate ones, which, however, seem to differ from one another more in detail than in principle.Take first those writers who still treat discrimination, imagination, etc. as isolated ' faculties ' : they obviously imply, however tacitly, that individuals excelling in one kind of discrimination must also excel in other kinds ; they assume, in fact, correlation between all performances belonging exclusively to the same ' faculty,' and absence of correlation between performances belonging wholly t o different ' faculties.'And the same applies, even though modified quantitatively, to the very numerous supportem of mental ' types I; when they classify people as ' visual,' ' auditory,' ' motor,' etc., or in any other more ingenious manner, they evidently imply that the different kinds of visual abilities tend to go together (except in so far as their ' types' merely refer to habits and preferences, not abilities).It is interesting to notice that even Thorndike appears to be surrendering his former belief in the complete independence of all mental powers, and t o be coming round to an opinion of the same class as those just mentioned.I n place of faculties ' or ' types he introduces the more cautious term of ' levels ' ; these he declares to be three in number, namely, sensitivity, association, and dissociation ; he says that performances correlate highly with those belonging to the same ' level,' lowly with those belonging to a different onea.I n all the views quoted in the last fiaragraph, each different faculty,' ' type,' or ' level ' is regarded as producing a separate focus of correlation ; all may be classed together as ' multifocal' theories.The theory of a general common factor, on the other hand, may be called