APA Dictionary of Psychology

an outdated diagnostic and classification category applied to those with IQs of 50 to 69, comprising 85% of people with mental retardation, the outdated and offensive term for intellectual developmental disorder (intellectual disability). Included in DSM-IV-TR, it was characterized by development of good communication skills and a sixth-grade level of academic performance by late adolescence, but without the social skill levels typical of adolescents. In DSM-5, the designation was changed to mild intellectual disability (intellectual developmental disorder), and, in DSM-5-TR, to mild intellectual developmental disorder (intellectual disability), with the level of severity defined on the basis of adaptive functioning, rather than IQ scores.