Reliability, criterion-related validity and qualitative comments of the Fourth Edition of the Stanford-Binet Intelligence Scale with a young adult population with intellectual disability.

Researchers gave the Stanford-Binet Fourth Edition (SB-IV) to 54 young adults with intellectual disability. They tested each person twice, five weeks apart, and also collected adaptive behavior scores from staff who knew them well.

The goal was simple: does the SB-IV give stable numbers, and do those numbers line up with how the adults actually cope at home, work, or day programs?

The IQ scores stayed almost the same across the five-week gap. The test-retest correlation was 0.89, which means high reliability.

SB-IV scores also showed a moderate 0.45 link with daily living skills. Higher IQ on the test matched better self-care, money handling, and social interaction in real life.

Haishi et al. (2013) tracked saccadic reaction time in adults with ID and found speed drops after age 30, especially in severe cases. Konstantareas et al. (1999) shows SB-IV stays stable in the same age window, so slowing eye movements do not seem to drag IQ scores down.

Fernández-Alcaraz et al. (2020) mapped a flat neuropsych profile in adults with Down syndrome. Their data line up with M et al.'s moderate validity numbers: no big splits between verbal and visual skills, just a steady, moderate link to adaptive behavior.

Anthony et al. (2020) found that adults with mild ID who lack a registered functional level often miss employment services. M et al. give you a quick, reliable tool to document that functional level and open doors to those very services.

If you need a fast, stable IQ estimate for transition planning, the SB-IV does the job in under an hour and holds steady for at least a month. Pair the score with an adaptive checklist to show funders why a client needs supported work or living funds. Re-test when big life changes hit—don't let aging or health issues sneak past you.