The use of the Vineland Social Maturity Scale, the Merrill-Palmer Scale of mental tests (non-verbal items) and the Reynell Developmental Language Scales with children in contact with the services for severe mental retardation.

Psychological tests were administered to a complete population of severely retarded children aged 0-14, from one area of south-east London. The fifty-six children selected for the present study included all those who had obtained scores on measures of social maturity, visuo-spatial skills not involving symbolic concepts, and level of language comprehension. The results show very low correlations between the age-related quotients obtained for each measure. This suggests that, in severely retarded children, marked discrepancies can occur between different areas of cognitive and social development. Some children could be classified as moderately or mildly retarded on one type of test but as profoundly retarded on another. The profiles on the tests can be related to diagnosis and behaviour pattern. The findings highlight the problems of assessment and educational placement of retarded children.