What is actually considered a low IQ? I know 100 is supposed to be average, but at what point does a score become “low” and what does that actually mean for someone’s daily functioning? Is there a specific cutoff or is it more of a spectrum?
Isn’t the scale set up so that 90-110 is considered average range? So would anything below 90 be low, or does it have to be significantly lower than that? And don’t different IQ ranges correspond to different levels of support someone might need in school or work?
IQ scores follow a bell curve with 100 as average and a standard deviation of 15 points. Generally, 85-115 is considered normal range, 70-84 is borderline or low average, and below 70 is where intellectual disability diagnosis begins (though functional assessment matters too, not just the number). Below 55 is moderate intellectual disability, and below 40 is severe. But context matters enormously. Someone with an IQ of 75 might function independently with support, while the score alone doesn’t determine life outcomes. Adaptive functioning, motivation, education, and support systems all play huge roles. The labels matter less than understanding what kind of accommodations or assistance might be helpful.