Sex differences in the classification of children as mildly mentally retarded

A consistent finding in epidemiological studies of mild mental retardation (MMR) is a somewhat higher prevalence of boys than girls. Our own study in Aberdeen agreed with these findings. Examination of the numbers of boys and girls at different levels of retardation within our study population revealed the greatest excess at the highest IQ levels of greater than or equal to 75. This was found to be true in other studies as well. Since this IQ range is above the generally agreed upon cut-off point used to classify children as MMR, these findings suggest that boys remaining in regular classes may be having more difficulty in school performance than girls. Possible reasons for this are examined.