It's true — there's a difference. The three terms didn't start out as social insults either, in fact. In the early 1900s, psychologists used the terms to describe various levels of retardation. Those with an IQ of 0 to 25 (an IQ of 100 is average) were called idiots, 26 to 50 were called imbeciles and 51 to 70 were called morons. Morons could communicate and learn common tasks; imbeciles stalled mentally at about six years old; and idiots couldn't respond to stimulus or communicate with any level of competency.
- The terms held until the 1970s when society decided they were demeaning or condescending. They were replaced with mild, moderate and severe.
- Down syndrome children first were called Mongolian idiots because their features were thought to look like people from Mongolia; Down syndrome first was called mongolism.
- Levels of retardation, or developmental disability, now are defined by more than just IQ — levels of mental and physical functioning are also considered.
- Signs of metal disability may begin with young children who crawl or walk or sit up later than their peers. They may also have a harder time memorizing information, speaking and interacting socially with other children.