The child has defi cits in intellectual functioning, which result in impairment in general mental abilities and adaptive functions in comparison to age, gender, and socioculturally matched peers. A developmental history suggests delayed milestones of development. Parents and teachers may report problems with reasoning, problem-solving, planning, abstract thinking, new learning, and judgment. They may report diffi culties in adaptive functioning, which results in failure to meet developmental and sociocultural standards for personal independence and social responsibility. There may be defi cits in activities of daily living, communication, social participation, and independent living seen across multiple settings such as home, school, and community.