Home > School and Learning > Learning Differences > Diagnosing Lds > The Difference Between LD and Mental Retardation

Expert Iconexpert advice MORE

The Difference Between LD and Mental Retardation

LD and ADD/ADHD Expert Advice from Jerome J. Schultz, Ph.D.

Q: My nine-year-old son was recently diagnosed as learning disabled and mentally retarded. I always thought those terms were interchangeable. What is the difference between them? His test scores show that he's of average intelligence in speaking and understanding speech, with an I.Q. of 105, but in all other areas his I.Q. is a 66.

A: To be considered mentally retarded (MR), a person's general intellectual functioning is well below average. People with this diagnosis have an intelligence quotient (IQ) of around 70 or less. People with mental retardation also have a significant impairment in the ability to handle the demands of daily living. This condition clearly has an impact on learning, communication, self-help skills, and social skills, during play or in a work setting. The degree of difficulty can range from mild to moderate to profound.

According to federal government statistics, about 1 out of every 100 people is mentally retarded, although some place this figure as high as 3 percent. Mental retardation is slightly more common in males than in females. It occurs in people of all racial, ethnic, educational, and economic backgrounds. For more information, go to the website of the American Association of Mental Retardation.

In contrast, a learning disability (LD) is regarded as a disorder in one or more of the processes involved in understanding and using spoken or written language. Learning disabilities show up in different ways in different individuals. They can have problems with visual perception (understanding or remembering what they see), which can make activities like reading letters or copying shapes very difficult. Or they can have problems with auditory perception (understanding or remembering what they hear) or using language to tell or write a story. A learning disability can cause difficulties in math, reading, writing, or spelling. Some people with a learning disability have organizational problems that can affect school or work.

People with learning disabilities generally have average or above-average intelligence. Their learning disability, however, creates a gap between ability and performance. They tend not to do well in environments that aren't suited to their learning style, but they can learn very well when taught appropriately. Learning disabilities often run in families. Fifteen percent of the U.S. population, or some 39 million Americans, have some form of Iearning disability. About 50 percent of all public-school students in special education have learning disabilities.

LD and MR are two distinctly separate conditions, and the terms are absolutely not interchangeable. If tests scores suggest that your son has a verbal IQ (that is, his ability to use and understand language) of 105, that's right in the middle of the average range. You say, "in all other areas his IQ is a 66." This might mean that his non-verbal skills, (that is, his eye-hand coordination and his visual perception) are extremely weak. This much of gap between verbal and performance IQs (the two major parts of an IQ test) suggests that at some point your son experienced a trauma to his brain that affected the centers that control non-verbal skills. So "by the numbers" he functions like someone with mental retardation in the visual perceptual areas. His verbal intelligence is clearly in the average range. If you blend these two scores together, you would get an overall IQ that would be in or close to the cut-off for mental retardation.

While it would be inappropriate to suggest a diagnosis from the information you've provided, this sounds like the profile of a student who has a significant non-verbal learning disability, or an impairment in the visual-perceptual-motor functions of the brain. For more about this condition, see www.nlda.org.

More on: Expert Advice

Jerome (Jerry) Schultz is the founding clinical director of the Learning Lab @ Lesley University, a program that provides assessment, tutoring, and case management services for children with learning challenges. Schultz holds a Ph.D. from Boston College, and has completed postdoctoral fellowships in both clinical psychology and pediatric neuropsychology.

Please note: This "Expert Advice" area of FamilyEducation.com should be used for general information purposes only. Advice given here is not intended to provide a basis for action in particular circumstances without consideration by a competent professional. Before using this Expert Advice area, please review our General and Medical Disclaimers.


10 Best Creative Apps for Kids
Looking for apps that foster creativity? Check out these top-rated art and music apps for kids.

Kindergarten Readiness App Wins Gold
Our Kindergarten Readiness app won the Gold Award of Excellence in the educational category at the 2014 Communicator Awards. This valuable checklist comes with games and activities to help your child practice the essential skills she needs for kindergarten. Download the Kindergarten Readiness app today!

A New Intergalactic Reading Adventure!
Get your reluctant reader hooked on an irresistible new story, Galactic Hot Dogs! Join the Book 1 reading marathon, and get behind-the-scenes tidbits on the official Galactic Hot Dogs blog. Also, print this cool Galactic Hot Dogs reading log to keep your bookworm excited about reading!

Find Today's Newest & Best Children's Books!
Looking for newly released books for your child? Try our new Book Finder tool to search for new books by age, type, and theme, and create reading lists for kids!

stay connected

Sign up for our free email newsletters and receive the latest advice and information on all things parenting.

Enter your email address to sign up or manage your account.

Facebook icon Twitter icon Follow Us on Pinterest

editor’s picks