Incidence
By Rondalyn V. Whitney, MOT, OTR/L

Once thought to be rare, NLD is now thought to be as prevalent as dyslexia. Estimates place NLD occurrence between 1 in 1000 to 1 in 50, suggesting that one child in every classroom has NLD. Dr. Kathryn Stewart has worked extensively with children with neurocognitive disorders such as Asperger’s and NLD in the Berkley California area. In her presentation at the 4th annual NLD symposium (1999) Dr. Stewart suggests NLD occurs less frequently than language based learning disorders and is predicted to be 10% of those with learning disabilities or about 1% of the general population. Therefore, for every 100 students in a grade level (assuming there are 30 students in 3 classrooms) one child would be expected to have some degree of impairment significant enough to meet the diagnostic criteria of NLD. Unlike language based disorders, NLD appears to equally affect males and females.

Why all of a sudden are there so many cases of NLD? Again, no one knows but several theories make sense. For example, the theory of genetics. Many children with NLD have parents who have some pieces of the NLD symptom criteria. Maybe mom has trouble with visual-spatial organizational skills, say at 20% impairment and dad has difficulty with peer relations at 50% impairment along with some mild deficits in visual-spatial-organization (say 15%) and then they pass on those weaknesses, little Sammy has 50% impairment of in peer relations and 35% deficits in visual-spatial-organization.. Of course, more research is needed to quantify the genetic component but many clinicians report, anecdotally, that parents and children are easily paired in waiting rooms. Or, to quote one clinician, “The genetic component always reveals itself”.

The theory of environmental toxins, effects of working with computers, later life pregnancies in career oriented men and women, and our stressed lifestyles have all been proposed as possible causes of increased incidents of learning problems in our children.

But the theory that makes the most sense to me, as an occupational therapist, is to look at the changes in our society, our lifestyles and changes in our family dynamics. To take a historical perspective, 30 years ago if a child was born with, say, a 50% deficit in motor skills and had a 95% strength in verbal skills that was a large enough gap that today, we may call it NLD. However, the lifestyles 30 years ago demanded children play inventively. They ran and rode bikes from morning till sundown. They explored in the woods and climbed trees for hours. They played hop-scotch, jacks, and stick ball immediately after school and on the weekends. They played with a small circle of friends who lived within walking or bike riding distances from their homes. Parents didn’t have two cars, typically, and children were left to play with friends who were in walking or riding distance. Peer circles remained fairly stable over many years as there was not a great deal of moving around. The academic demands were simple, concrete and expectations were pretty clear. Recesses were long (20 – 30 minutes) and occurred twice a day and lunch was an extended period. Children climbed trees, monkey bars, played on teeter-totters and swings. The amount of visual, proprioceptive, vestibular and tactile experience was profound and pervasive. The amount of social skill development was exceptional as well. The opportunity to devour information was low. A family may travel to the local library on Saturdays but they didn’t have access to much of the world, and certainly not at the click of a mouse or the push of a remote’s button as it flew over 65 channels on television. Extended families were the norm, neighbors felt free to intrude into a gang of rowdy children and many caregivers were around to coach children on appropriate ways of behaving. Play was unstructured. Academic requirements began in first grade and maybe, at age 5, in kindergarten or Headstart.

In the 90’s and now in the 00’s (the Millenium O’s my son calls this decade) we require children as young as 3 to sit in a circle of 20 other children and attend to one adult. We expect them to follow directions, to draw pictures according to the assignment. We read to our children early and celebrate when they begin to read at age 3. We put a pencil into the hands of a 4 year old and encourage them to write their ABC’s. It’s not enough to learn the alphabet these days but children need to learn how to respond to a two dimensional visual prompt on a computer when Grover (from Sesame Street) holds up a number. We keep our children inside because it is not safe to let them roam the community and play. They ride bikes, when they do, on our 5 foot long driveways where we can see them. If they are in a structured academic pre-school, they don’t have the opportunity to pull pans from the shelf, bang them, and learn visual organizational skills of replacing silverware in a drawer that got pulled out, again, during routine exploration.

This is all not to say that preschool is causing NLD and other learning disorders. But it seems important to look at that child who is born with 50% motor and 95% verbal skills. Thirty years ago, the 50% motor skills developed to say, 70 or 80% due to every day life and the demands and opportunities available to the child and they were completely functional. The 95% verbal skills set the child up for success in school and since the school provided structured, predictable assignments, for the most part, the child succeeded. Now, in the year 2000, we have children who increase their rote knowledge daily. Born with a 90% strength in verbal skills and other strengths associate with NLD such as a rote memory for facts, these children can surf the internet and acquire vast amounts of factual information. They can become experts in bats, or trains, or Pokemon through an environment enriched with technology, books, magazines aimed at children, and television. However, they have less opportunities to engage in casual social interactions or motor skill development. Play dates are arranged weeks in advance to accommodate busy schedules. Children spend hours learning factual information. The gap between performance (motor skills) and verbal widens rather than shrinks. By the time a child enters school, they have vast knowledge but impoverished skills in moving their hands together in simple tasks. A child with a 50% deficit in motor skills has now regressed to 40% while simultaneously their verbal skills have increased to 99%. This gap, indicative of NLD, has grown to the point of being disabling to a child.

It is no surprise to me that interventions in the areas of movement, social relationships, and visual-perceptual development are the areas that provide the most success. It is a surprise to me that as a society we haven’t stopped to examine the consequences of enriching part of our children’s minds but leaving the body and spirit impoverished. (Note: As a parent of a child with NLD, and as therapist, I too am guilty of providing all the books my son wanted but not challenging him to move and explore his world, to get to know his body as it moved in space and time and to understand the environment more kinesthetically.) It certainly seems to me that environmental changes, viewed from a historical perspective, must be considered when exploring the “causes” of nonverbal learning disorders.