Intellectual disability is a developmental disorder characterised by limitations in intellectual functioning (reasoning, learning, problem-solving) and adaptive behaviour (communication, social and practical skills). This disability originates before the age of 18, and the individual faces more difficulty than others in thinking, learning, and independence.
Intellectual disability is not an illness or disease, but a condition which can occur anytime before, during, or after birth (before 18 years of age). Genetics also play a part as an intellectual disability may occur via the genetic transmission of traits from parents to offspring.
Intellectual Functioning refers to general mental capacity, such as learning, reasoning, problem-solving, etc.
Adaptive Behaviour comprises three skill types – conceptual skills, social skills, and practical skills.