The correlation of g with attentional and perceptual-motor ability tests

The correlation between tests of psychometric g and tests of attentional and perceptual-motor abilities was studied. These tests are generally seen as representing three different taxonomies. Test scores of 584 applicants for jobs at Dutch Railways and bus companies were used. The correlation between the g score of the cognitive test and the various parts of the attention-psychomotor battery ranged from 0.14 to 0.56 with 0.39 as an average. Structural-equations modeling using EQS resulted in a general cognitive factor and four second-order factors: Fluid/Crystallized Intelligence, Broad Visual Perception, general Attentional Speed and general Perceptual-Motor Ability, accounting for, respectively, 54, 15, 11, 4, and 16% of the variance. This study has shown that there is substantial overlap between these three taxonomies. The great majority of the attentional and perceptual-motor tests show substantial overlap with psychometric g. However, there is still enough unique variance connected to these tests to result in a weak Attentional Speed and a strong Perceptual-Motor Ability factor. It is most probable that inclusion of the factor scores of broad lower-order factors into a prediction formula using g results in small incremental criterion-related validity for General Attentional Speed and larger gains for General Perceptual-Motor Ability.