Table 1.

Intellectual Disability (ID) Criteria

ID Criteria	Definitions
	APAa	AAIDDb
Criterion A: Intellectual Functioning Limitation	“Deficits in intellectual functions such as reasoning, problem solving, planning, abstract thinking, judgement, academic learning, and learning from experience, confirmed by both clinical assessment and individualized, standardized intelligence testing” (test score ≤ 75) (p. 33).	“Significant limitations in intellectual functioning” (p. 27) including learning, reasoning, problem solving, etc.
		IQ standardized test score cutoff approximately two standard deviations from population mean
Criterion B: Adaptive Functioning Limitation	“Deficits in adaptive functioning that result in failure to meet developmental and socio-cultural standards for personal independence and social responsibility. Without ongoing support, the adaptive deficits limit functioning in one or more activities of daily life, such as communication, social participation, and independent living, across multiple environments, such as home, school, work, and community” (p.33).	“Significant limitations in adaptive functioning” (p. 27).
		Composed of limitations in:
		• conceptual skills
		• social skills
		• practical skills
		Standardized score of adaptive behavior approximately two standard deviations below mean on one type of adaptive skill or overall score of all three skills
Criterion C: Disability during developmental period	Onset of both intellectual and adaptive deficits during the developmental period of childhood or adolescence	Onset before age 18

^aAPA (American Psychiatric Association) (American Psychiatric Association, 2013)

^bAAIDD (American Association on Intellectual and Developmental Disabilities) (Schalock et al., 2010)