THE REAL ERROR OF CYRIL BURTmathematics of correlation. But factors, by themselves, are neither
things nor causes; they are mathematical abstractions. Since the
same set of vectors (see Figs. 6.6, 6.7) can be partitioned intog and
a small residual axis, or into two axes of equal strength that identify
verbal and arithmetical clusters and dispense with g entirely, we
cannot claim that Spearman's "general intelligence" is an ineluct-
able entity necessarily underlying and causing the correlations
among mental tests. Even if we choose to defend g as a nonacciden-
tal result, neither its strength nor its geometric position can specify
what it means in causal terms—if only because its features are
equally consistent with extreme hereditarian and extreme environ-
mentalist views of intelligence.6*7 Rotated factor axes for the same four mental tests depicted in Fig.
6.6. Axes are now placed near vectors lying at the periphery of the cluster.
The group factors for verbal and mathematical aptitude are now well
identified (see high projections on the axes indicated by dots), but g has
disappeared.