On the other end of the scale, we have the lower than average intelligence that used to be called mental retardation and is now referred to as intellectual disability
Intellectual Disability Less than average intellectual functioning; the person is unable to perform tasks appropriate for his/her age.
These intellectual disabilities can be classified into five different levels. IQ scores of the intellectual disabled fall below 79. Why do intellectually disabled people "look different" than the average person? About 20% of people who are intellectually disabled have suffered from a physical defect usually resulting in a brain trauma. This brain trauma may have been caused by a lack of oxygen at birth, exposure to toxic chemicals, or poor nutrition. The brain has been compacted or stretched and looks different than the average person’s brain. Therefore, the intellectually disabled person will "look" different and their thoughts and behaviors are slowed. How do we treat the intellectually disabled? For those whose IQ scores that fall between 52–79, mainstreaming is a great alternative for their education. In some school districts, the intellectually disabled will be in an inclusion type of classroom for most of their day and a mainstreamed classroom for elective courses.
Mainstreaming Placing mildly mentally retarded children into classes with average IQ score children.
Inclusion A classroom for mentally retarded children where all of their learning takes place
View the Intellectually Disabled classifications.