An Alabama man challenged his death sentence after a murder conviction because of his varying results in a series of I.Q. tests.

Since the latter part of the 19th and early 20th centuries, intelligence tests have attempted to measure human intellectual capabilities. The most common assigns an intelligence quotient, or IQ, score ...

On Thursday, the US Supreme Court ruled 5-4 to dismiss the Hamm v. Smith case, effectively upholding its rulings that people with intellectual disabilities should not be executed, ...

If Pervis Payne is determined to have an intellectual disability, he could be saved from execution. But first he will face a week-long hearing in which experts, his family and others will testify ...

Intellectual disability is a disorder marked by below-average intellectual function and a lack of skills necessary for independent daily living. The condition begins in the developmental period. The ...