Ranges are based on Weschler Adult Intelligence Scale (WAIS)
Class: Profound Retardation IQ: Below 20
Class: Severe Mental Retardation IQ: 20-34
Class: Mental Retardation IQ: 35-49
Class: Mild Mental Retardation IQ: 50-69
Class: Borderline Deficiency IQ: 70-79
Each child is able to learn, develop, and grow to an extent. Their capacity to experience joy and human relationships with those around them is not IQ-dependent.
IQ (60-70): About 87% of those with a developmental disability will be a little slower than normal in learning new information. Mild disability may not be evident or even diagnosed until they school. Even if poor performance levels are recognized, it may take expert assessment to distinguish mild mental disability from a learning disability or behavioral problem. As they become older some can grow and be considered "slow" rather than "Retarded" based upon their progresses.
IQ (50-60): Moderate disability is obvious within first year of life. They will encounter difficulties in school, home and in the community. In many cases special schooling will be needed, or specialty classes but can progress and become functional members of society.
IQ (50-BELOW): Those with more severe cases will need support their entire life.