Most forms of mental retardation are recognized early in a child’s life, as children fail to achieve standard developmental milestones at appropriate ages or clearly display unusual behaviors. Mental retardation is diagnosed in the 2% to 3% of children who score the lowest on a standard IQ test and are delayed to the same extent in such life skills as self-care, selfdirection, and the use of academic skills. Eighty-five percent of children with mental retardation fall into the mild range, with IQ scores from 50 to 70. Experts use these lower IQ scores to label a child as mildly, moderately, severely, or profoundly retarded. The majority of children with below-average IQ scores are not considered to be mentally retarded, but below average, with test scores between 70 and 89.