Does a low IQ score matter? Mental retardation becomes Intellectual Disability.

By David Joel Miller, MS, Licensed Therapist & Licensed Counselor.

Could you be mentally ill?

What Causes Mental Illness?

Mental retardation becomes Intellectual Disability.


How much do I.Q. scores tell us?

There has been a lot of misunderstanding about I.Q. Scores, what they mean and just how significant a low I.Q. score may be. Some of the things we thought we knew have been challenged recently.

One definition of an I.Q. score is “The number of marks you make correctly on a piece of paper divided by your age.” We expect younger people to get lower scores and older people to get higher scores. What this does not tell us is what those scores are really measuring and what difference does it make.

The conventional belief is that people with low I.Q. scores are less mentally able.

This presumes that there are no biases in the test. Most test manufacturers or publishers work long and hard to eliminate biases. Still, we know that culture matters. Most I.Q. tests rely heavily on words, so if you speak two or more languages, but as a result know fewer words in each language you speak, you might score lower.

The presumption in the past has been that the higher you score on the I.Q. test the smarter you were and the better you should do in life. For someone with a low I.Q. we assumed that learning things would be harder.

This does not explain how someone with a low I.Q. score might be very good at a skill like music or a sport while the person with a high I.Q. might fail at those same skills.

Clearly I.Q. is not the whole story.

The mean I.Q. score is set at 100. The way I.Q. mathematics works are that the majority of people get scores from 85 to 115. That range is considered normal. So mix children with I.Q. scores of 85 and 115 together in a class and the teacher might have difficulty telling which is which, without reference to their test scores.

But if you get a score of 84, now we say you have “Borderline intellectual function.” If the 30 point differences between “normal” don’t make much difference how does that one point difference between 84 and 85 make so much difference?

The truth is small differences don’t make that much difference.

What matters most is what people do with the intelligence they have. So just like the really heavy kid may be no good at football and the skinny little kid may be able to run really fast with the ball, so to differences appear in how people use the intellectual resources they have.

The trend in the DSM-5 to move towards dimensional diagnosis rather than categories has changed our thinking from classifying mental retardation based on I.Q. scores to looking at how that low I.Q. is affecting the person.

So if the person is having difficulty with adaptive functioning because of their intellectual disability they get diagnosed with an intellectual disability disorder. If they are doing a good job of functioning despite a low I.Q. score they just may not get a diagnosis.

I realize this will take a while for the popular culture to catch up. It is no longer your I.Q. score that matters but what you do with what you got.

This shift by therapists and the APA is also likely to cause ripples in all that special education and those government programs that are still using I.Q. scores as a basis for services.

All in all, I see good and bad in this. Good if it reduces stigma against people simply because of the score they got on one piece of paper and bad if as a result of new definitions some people who need help get screened out.

Only time will tell.

So till then stop saying people have mental retardation and look to see if they are having difficulty coping with their life because of an intellectual disability or are they just sad, anxious or upset about life events like the rest of us.

Staying connected with David Joel Miller

Two David Joel Miller Books are available now!

Bumps on the Road of Life. Whether you struggle with anxiety, depression, low motivation, or addiction, you can recover. Bumps on the Road of Life is the story of how people get off track and how to get your life out of the ditch.

Casino Robbery is a novel about a man with PTSD who must cope with his symptoms to solve a mystery and create a new life.

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For more about David Joel Miller and my work in the areas of mental health, substance abuse, and Co-occurring disorders see my Facebook author’s page, davidjoelmillerwriter. A list of books I have read and can recommend is over at Recommended Books. If you are in the Fresno California area, information about my private practice is at

4 thoughts on “Does a low IQ score matter? Mental retardation becomes Intellectual Disability.

  1. Pingback: It’s what you do with what you’ve got that matters | Sheila Allee – Author

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