Behaviour Charateristics of the Mentally Retarted in a State Mental Hospital—a Comparative Study1

30 institutionalised severely subnormal (SSN) subjects and 30 matched severely subnormal individuals attending the outpatient services of the Institute of Mental Health, Madras were evaluated for their behaviour characteristics using a schedule containing two scales,the social and physical incapacity (SPI) scale and the speech, self help and literacy (SSL) scale. Destructive behaviour, self injury, overall poor speech, self help and literacy ability, overall social and physical incapacity, poor speech ability, poor speech comprehensibility, poor self help and poor literacy were the discriminating factors much more common for the institutionalised subjects than for the outpatient individuals. The usefulness of this informations in the planning and implementation of services for the institutionalised mentally retarded is discussed.