PROVE IT: Someone with intellectual disability has limitations in two areas. These areas are: Intellectual functioning. Also known as IQ, this refers to a person’s ability to learn, reason, make decisions, and solve problems. Adaptive behaviors. These are skills necessary for day-to-day life, such as being able to communicate effectively, interact with others, and take care of oneself. IQ (intelligence quotient) is measured by an IQ test. The average IQ is 100. A person is considered intellectually disabled if he or she has an IQ of less than 70 to 75.