How ‘flat’ are normal ability profiles in 4-year-olds?

Summary Group and individual ability profiles of 89 English 4-year-olds on the McCarthy scales of children's abilities (MSCA) are presented. The results suggest that at this age, there is a high expectation of obtaining at least one significant difference between a child's mean ability score and the individual ability of index scores. The direction of these significant differences in ability suggested that, in this age group, abilities measured by the MSCA verbal and perceptual performance indexes tend to be more advanced than abilities measured by the quantitative and memory indexes. Motor development is relatively retarded compared to these other abilities. (The results are at variance with the often accepted concept of a 'flat' ability profile in normal children.)
The use of the MSCA on English children could result in over referral of normal children, especially boys, who appear delayed on the motor index, and under referral of children who were regarded as normal on the verbal and perceptual indexes.