title: Mental subnormality in Northern Ireland.
abstract: A prevalence survey of mental subnormality in Northern Ireland was carried out on lines similar to an earlier investigation by MacKay (1971). In a general population of one and a half million there were 6,854 ascertained subnormal individuals. The male : female ratio was 1. 14 :1. Approximately one in three subnormal people was under residential care. The prevalence of severe subnormality (IQ less than 50) in the 15-19 year old group was 4.81. The findings do not support the "steady rate" theory of severe subnormality.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D003156:Community Mental Health Services; D005260:Female; D006778:Hospitals, Psychiatric; D006801:Humans; D007223:Infant; D008607:Intellectual Disability / Q000453:epidemiology*; D007360:Intelligence; D008297:Male; D008875:Middle Aged; D009660:Northern Ireland