Two individuals with intellectual disability may both be classified with mild intellectual disability, but one may hold a job and be married, while the other may need to be cared for by others in a care facility. this is one reason that deficits in behavior are now included in the definition of intellectual disability.

This is one reason that deficits in ADAPTIVE behavior are now included in the definition of intellectual disability.

Explanation:

In the last update of the Diagnostic and Statistical Manual on Mental Disorders (DSM) the American Psychological Association (APA) recommended to use the adaptive functioning level over conceptual, practical and social skills, instead of IQ scores, as the reference for the severity levels of intellectual disability (mild, moderate, severe, profound). The construct of adaptive behavior is believed to be better as it is more inclusive and predictive.