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Facts - Intellectual Disabilities

After 22 years as an RN, I now write about medical issues and new medical advances. Diet, exercise, treatment, and lifestyle are important.


Intellectual Disability Facts

Intellectual disability (mental retardation) is characterized by below average intelligence or by someone with a mental ability that lacks the necessary skills to help themselves complete the normal skills for daily living. Mental retardation is present in 2-3% of all children, but it is more common in boys. There are many causes of mental retardation, but the cause is unknown in two thirds of all cases. Basically, anything that interferes with normal brain development can cause an intellectually disabled child.

The two most common causes of intellectual disability are the genetic conditions of Down's syndrome and Fragile X syndrome, however, there are some other causes of mental retardation that include genetic and environmental factors. Autism spectrum disorder (ASD) is another genetic condition that causes various degrees of intellectual disability, and a 2019 study involving over 2 million people from 5 countries found that autism spectrum disorders are 80% reliant on inherited genes.

The degrees of intellectual disability range in 5 categories, including: borderline, mild, moderate, severe and profound.

Some other reasons that may cause mental retardation include:

  • Problems during pregnancy - includes drug or alcohol use (fetal alcohol syndrome), severe maternal malnutrition, some particular infections and preeclampsia
  • Problems during childbirth - a baby receiving an inadequate amount of oxygen and a baby born very prematurely
  • Illness or injury - infections such as measles, whooping cough, measles, meningitis, severe head injury of mother or a near drowning
  • Exposure to toxic substances such as lead, mercury, etc.

What Exactly Is Intellectual Disability?

There are actually two areas of limitations in an individual's intellectual disability, they include:

  1. Intellectual functioning is the IQ that refers to an individual’s ability to reason, learn, make decisions and to solve problems.
  2. Adaptive behaviors are those life skills necessary on a day-to-day basis, which includes the ability to communicate effectively, to interact with others and to take care of themselves.

The IQ (intelligence quotient) is measured through testing, and the average person’s score is 100, with a normal range between 85 and 115. A person with an IQ of less than 70 to 75 is considered intellectually disabled and their inability to complete two or more adaptive skills. Problem solving, abstract reasoning and planning ahead are also problem areas.

There is no accurate figure for the number of mentally retarded children in the USA, let alone in the whole world. Down’s syndrome and Fragile X syndrome are common causes of mental retardation, and they can be diagnosed during gestation. The testing is simply not being done across the country that would give us some actual statistics.

Diagnosis Intellectual Disability

The diagnosis of a child with an intellectual disability requires a comprehensive personal examination and family personal history. A developmental assessment of the child should also be completed.

Only 3% of patients have the inherited chromosomal anomaly for autism. The innumerable factors associated with mental retardation may be chromosomal, of which some are metabolic and some are genetic.

There are 3 common problems that may be frequently missed with young children, and they include:

  1. A conclusion that the child does not “look” retarded
  2. Assuming that an ambulatory child is not likely to be retarded
  3. If retardation is considered it is thought that the child is too young for testing.

Early Intervention at Children First


The Centers for Disease Control and Prevention (CDC) issued its ADDM autism prevalence report in 2018. It stated the prevalence of autism had increased to 1 in 59 people as compared to 1 in 125 people in 2004. That rise is certainly concerning and there is no known single cause for the autism spectrum disorder, although it is accepted that abnormalities in the brain structure are different for those children with autism. The shape and structure of the brain will show abnormalities in a brain scan. There are several subtypes of autism, as it is influenced by a combination of genetic and environmental factors. Despite extensive research, there is no connection between childhood vaccines and autism.

As an autism spectrum disorder each individual will have a distinct set of strengths and challenges. At one time “autism, Asperger’s syndrome, childhood disintegrative disorder and even an unspecified form of pervasive developmental disorder” were previously considered separate disorders, but that is no longer the case. Asperger’s syndrome is now thought to be at the milder end of the autism spectrum disorder.

Symptoms of Autism

A baby may be developing normally until they reach 2 to 3 years, although some symptoms can show up by 18 months. The baby may not make eye contact or around 2 years the baby may become withdrawn and stop saying those few words they recently learned.

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Positive outcomes may be achieved for people with autism when they have early, intensive intervention. Some people with ASD will forever need substantial support in their daily lives and others will live independently.

Several factors influence the development of autism, and it is often accompanied by other medical issues, including gastrointestinal disorders, seizures or sleep disturbances. Anxiety, depression and attention issues may also be a problem.

Conditions that put a child at a higher risk of ASD include:

  • Boys are 4 times more likely to develop ASD than a girl
  • The risk of having another child with ASD is higher when there is already a family member with ASD.
  • Babies before 26 weeks of gestation are at a higher risk.
  • Other medical conditions that increase the risk of ASD are the fragile X syndrome, tuberous sclerosis, a condition in which benign tumors develop in the brain; and Rett syndrome, a genetic condition occurring almost exclusively in girls
  • Older parents may have a greater risk of having a baby with ASD, but this has not been proven yet

Social interactions and communication skills are often a problem for the child with ASD, along with the difficulties of raising a child with an intellectual disability, which leads to:

  • Stress in the family
  • Problems in school and learning
  • Inability to live independently
  • Employment problems
  • Social isolation
  • Victimization and being bullied

Treatments for Children with Intellectual Disability

First, vision and hearing problems must be ruled out. There is no simple cure for intellectual disabilities, but children must learn to add and recognize letters in elementary school to move forward with their education. Some children benefit from occupational therapy or other types of professional help.

When children are not successful in schools they can become depressed, have low self-esteem, performance anxiety and they may have a loss of motivation. A math tutor or reading specialist may help tremendously.

Kodi Lee, a singer and musician, who is blind and has autism, wins and he won 'America's Got Talent' in 2019.

Kodi Lee: America Loves Kodi

In Summary

Intellectual disabilities are a lifelong issue. Development disabilities can obviously be very difficult for the whole family while raising this child. Social skills, communication, relationships and the ability to care for one’s self impact the quality of life for the whole family. The degree of the disability will impact the required care.


This content is accurate and true to the best of the author’s knowledge and does not substitute for diagnosis, prognosis, treatment, prescription, and/or dietary advice from a licensed health professional. Drugs, supplements, and natural remedies may have dangerous side effects. If pregnant or nursing, consult with a qualified provider on an individual basis. Seek immediate help if you are experiencing a medical emergency.

© 2020 Pamela Oglesby


Pamela Oglesby (author) from Sunny Florida on October 26, 2020:

Hi Maria,

An 86 year old has it tough enough anyway I imagine. Your hurband sounds like a good man. I thought of the famiies, especially for those who don't function at a very good level. Thanks for commenting, Maria.

Maria Jordan from Jeffersonville PA on October 25, 2020:

Hi Pamela,

I agree with the comments that address the toll that children (adults) with intellectual disabilities can take on the family.

My husband is a case manager with this population. One of his clients lives with his 86 yo Mother and she is so grateful for the relief when my husband takes him out for the day.

Thanks for your sensitive discussion of this family issue. Love, Maria

Pamela Oglesby (author) from Sunny Florida on October 22, 2020:

Hi Vidya,

You know first hand all the problems that can occur when you are raising a child with an intellectual disability. Thank you for sharing your personal experience and for making such very nice comments.

VIDYA D SAGAR on October 22, 2020:

Dear Pamela, another excellent article, enlightening us on so many aspects of intellectual disabilities. I have seen a child of a distant relative with this disability. The struggle they put up with caring for the child is really heartbreaking. As you said it affects the whole family as these children need special care and attention all the time.

Pamela Oglesby (author) from Sunny Florida on October 20, 2020:

Hi Peggy,

You are fortunate to have that type of mother. I think she trained you well. I always enjoy hearing from you.

Peggy Woods from Houston, Texas on October 19, 2020:

Hi Pamela,

My mother did have a huge heart and was always reaching out to help people in ways that she could. She did volunteer work of one sort or another almost her entire life. The example I gave was just one example.

Pamela Oglesby (author) from Sunny Florida on October 19, 2020:

Hi Ms Dora,

I agree that we need to take care of these children with special needs. Maybe some cure will be found. Kobe Lee is amazing.

Thanks for your comments. Have a good wekk!

Dora Weithers from The Caribbean on October 18, 2020:

Thanks for the facts. It looks bleak in some parts, then comes Kodi Lee who adds a world of inspiration. Let's just continue doing what we can to care for these special individuals.

Pamela Oglesby (author) from Sunny Florida on October 17, 2020:

Hi Sp,

I think it is always good to have more knowledge about a condition like these. The support networks can make all the difference in a better quality of life. Thank so much for your very nice comments.

Pamela Oglesby (author) from Sunny Florida on October 17, 2020:

Hi Devika,

I think you are absolutely right concerning family support. The more support the child has the better their chance of having a good life. I appreciate your comments.

Sp Greaney from Ireland on October 17, 2020:

I definitely think that people need to know more about the different types of intellectual disability out there. This was a very interesting article that really gave you a better understanding of the causes of this condition.

If more support networks were there from the start for a parent then at least they can help get their child started on the right path to be semi self sufficient as early as possible.

Devika Primić from Dubrovnik, Croatia on October 17, 2020:

Hi Pamela, this is interesting and in detail explaining of the disabilities. There is hope for such cases and in every case family support is key to confidence and happyness for the individual to avoid depressive minds.

Pamela Oglesby (author) from Sunny Florida on October 17, 2020:

Hi Liz,

That is an interesting story. She took some excellent action instead of just being mad at inconsiderate people. She has enough to do without having to put up with those people and something good has come out of her frustration.

I appreciate your comments, Liz. Have a good weekend.

Pamela Oglesby (author) from Sunny Florida on October 17, 2020:

Hi Linda,

I agree with Chitrangada's second paragraph too. From everything i have read the earlier you get help the better chance you have for a fairly normal life. Kobe Lee is an amazing man as he sings and plays the piano so well with his disabilities. I think we have a lot of learn about the brain. Thanks so much for your comments. Have a nice weekend, Linda.

Pamela Oglesby (author) from Sunny Florida on October 17, 2020:

Hi MG,

The left cheek is where my knowledge base ends. Haha Thanks for your comments.

Pamela Oglesby (author) from Sunny Florida on October 17, 2020:

Hi Flourish,

I know it must be hard for parents to care for a child throughout his while life. It is sad and I really didn't get into Down's Syndrome too much in the article. The amount of information is just about over whelming. Thanks for sharing your personal experience and commenting.

Liz Westwood from UK on October 17, 2020:

This is an interesting and, as ever, well-presented article. In the UK we use the term 'learning disabilities'. I was interested this week to see a report of a mother of a toddler who has Downs syndrome. She was fed up with the way that people talked about her child and the incorrect and hurtful terms that they used. So, during lockdown, she designied a series of cards to teach people how to talk about her child. The cards have been so successful that her local hospital has them on slideshows on screens in waiting rooms and there has been national interest.

Linda Crampton from British Columbia, Canada on October 16, 2020:

This is another very informative article, Pamela. People with intellectual disabilities should get all the help that they need. I agree with Chitrangada's second paragraph very much. We may be surprised by what some people classified as having a disability can achieve.

MG Singh emge from Singapore on October 16, 2020:

Hi, Pamela, you are a great source of information. Can you advise what's to be done if the left cheek vibrates once in a way?

FlourishAnyway from USA on October 16, 2020:

I had a cousin who had Down’s Syndrome and lived to his fifties. His immediate family kept him with them at home until his elderly parents could no longer care for him, at which time both he and his mother went into separate care facilities.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Linda, I agree that the numbers for auutism might be wrong as it may be not well understood. Underdiagnosed is surey a possibility. I know from everything I hae read tht eally diagnosis makes a huge difference. These children can surely have a good, full life.

Linda Lum from Washington State, USA on October 16, 2020:

Pamela, by the way, regarding autism, my theory is not that it is on the rise but that it is better understood and is being diagnosed and recognized more than it was in the past. With early intervention, children with mild autism can learn to live near normal lives.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Linda,

This was a difficult article to write i a way as I didn't know what you neded to hear. I hope I answerd some of your questions.

This is such a broad topic that I didn't necssarily think I covere what you wanted to hear. If there is something more specific please let me kow. I know you are right about people fearing what they do not understand. Thank you for your comments.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Peggy,

I wonderd why autism was on the rise also. It is certainly concerning and I hope we get some answers in the near future.

It sounds like your mother had a big heart and it is a shame the child was such a problem. It really makes you think about what families have to deal with when a child has autism or any other intellectual disability.

I appreciate your comments, Peggy, as always. Have a wonderful weekend.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Anika,

The Fragile X syndrome is just one more horrible mental disorer, I am glad this articlle was interesting to you and offered new information. Thank you so much for your comments.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Sgfgree that Kobi hauna,

I agree that Kobi is breath of fresh air. For someone with his diabilities he is truly amaizng. I would have loved a class like you had. I think we need to consider what someone with a disabiloity still has to offer.

Thank you so much for your generous comments. They are much appreciated.

Linda Lum from Washington State, USA on October 16, 2020:

Pamela, thank you for covering this topic. I know a young man with Fragile-X; as he ages (now mid-30's) he is becoming more difficult for his parents to handle. I do worry about him. I was surprised to learn that 2/3 of those with a disability do not identify a specific cause. That is the case with my daughter. She is high-functioning, but childlike.

Thank you for shedding light on this problem; people fear what they do not understand.

Peggy Woods from Houston, Texas on October 16, 2020:

I wonder why autism seems to be on the rise compared to days in the past? Perhaps someday we will have the answers. Your article points out some genetic reasons, as well as the possibility of other factors causing these conditions of children having intellectual disabilities.

My mother once took a neighbor's child into our home for a week to give the parents a break. My brothers and I still lived at home. One of the worst aspects is that the child did not want to bathe. She was a teenager so it was harder to control her behavior. My mother used her best psychology to encourage her to bathe. Needless-to-say, it was pretty smelly if near her. It was a relief for all of us when she went back home. It gave me a sense of what her parents had to deal with on a daily basis in just that one aspect. There were other problems as well.

Ankita B on October 16, 2020:

Really interesting to know about the intellectual disabilities. I was not familiar with the Fragile X syndrome before. Thank you for sharing this excellent article.

Shauna L Bowling from Central Florida on October 16, 2020:

Pamela, this is a very comprehensive article. Thank you for posting it.

When I was in high school, our psychology class spent a semester at a local school for the mentally challenged. The children ranged from severely challenged to those who could perform tasks and qualify for jobs such as sorting nuts and bolts in a factory setting, bagging groceries, etc. It was very eye opening. One trait every child had in common was complete love and trust. They were the most loving people I'd ever met.

I'm glad you posted the video of Kodi. He's absolutely amazing! He's got such love and support from his family and now the world. That's pretty cool, if you ask me.

Great article, Pamela!

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Chitrangada,

This is a very complex issue and I cn only imagine the difference for a child when pareing aents, teachers and siblings help and make a positive impact. I imagine you saw many things as a former teacher.

I appreciate your generous comments. Stay safe and healthy.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Raymond,

You bring up a very point concerning the IQ. You sound like you know a little bit about these conditions maybe through some training. I am glad Fragile X is not so common also.

I am glad you found this article to be interesting and your comments are much appreciated.

Chitrangada Sharan from New Delhi, India on October 16, 2020:

Excellent information about intellectual disabilities. This is a complex health issue, and needs lots of support from the family and the teachers.

Being a former teacher, I have seen some cases closely. With the support of the parents and siblings, such children have done well in life, later on. So, I believe there is hope.

Thank you for sharing this wonderful article. As always very important and educational. Have a good day.

Raymond Philippe from The Netherlands on October 16, 2020:

I found this another interesting article of yours. Fortunately, Fragile X syndrome is not very common within the autism spectrum. I also sometimes wonder whether the emphasis on IQ does not detract from the other qualities a person can possess.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi JC,

Thank you so much for your very nice comment.

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Cheryl,

I am glad you found this article helpful. Thank you for your comment.

JC Scull on October 16, 2020:

Excellent article Pamela.

Cheryl E Preston from Roanoke on October 16, 2020:

This was very helpful

Pamela Oglesby (author) from Sunny Florida on October 16, 2020:

Hi Hertha,

I am gld you liked this article. Thank you so much for your comments.

Hertha David from Windhoek, Namibia on October 15, 2020:

Hi Pamela, this is an amazing article with great information well written. Thank you for sharing.

Pamela Oglesby (author) from Sunny Florida on October 15, 2020:

Hi Eric,

Your children make interesting examples of "God's in charge". I simply have no explanation as to why some improve and some just don't. Thank you for sharing your personal experience. Of course, I always appreciate your comments.

Pamela Oglesby (author) from Sunny Florida on October 15, 2020:

Hi Kalpana,

It is heartbreaking to see children make fun of another child who cannot help his problems or situation. That was a lesson for me as a child one time also. Parents should teach kindness.

Thank you so much for your comments.

Eric Dierker from Spring Valley, CA. U.S.A. on October 15, 2020:

So very interesting, thank you. My youngest daughter had more issues than you can shake a stick at. We held her back a year, attended meetings once a week, spent that extra time just talking and reading.

Something just clicked right at her teens. Academy president and full ride scholarship to Berkeley.

It was good to read of experts being somewhat baffled as I sure am. My eldest came out a "blue" baby and my youngest over a month premature. They are both off the charts smarts. Go figure.

There is a strange place where the intellect is in full gear but the emotional staggers. Thanks for such a well done piece.

Kalpana Iyer from India on October 15, 2020:

Very informative article Pamela. I witnessed someone with autism when I was a kid. We all were very young, so some of the kids did not really understand mental disabilities and made fun of this autistic boy. I was always an introvert, so I was more into observing back then. What I witnessed broke my heart, and ended up being a big life lesson on kindness. His little sister approaching their mom saying "They are making fun of my brother." I could see the mom a bit disturbed but she managed her emotions well and consoled the sister saying "They don't know any better."

This was a first-hand experience for me, and I still feel a flood of emotions remembering the scene. I hope along with adults, even children are taught to respect their counterparts different from them.

Pamela Oglesby (author) from Sunny Florida on October 15, 2020:

Hi Cheryl,

I think it is very interesting to see how different people act or react in different situations. I think children outgrow so many things, like arranging toys in a particular way. My mother was also very picky about the house and keeping everything clean. We all had chores!

Thank you for sharing your personal experience. I appreciate all of your comments.

Cheryl E Preston from Roanoke on October 15, 2020:

Thank you for addressing this issue. my mom had an issue with keeping things neat when i was young. As a child I was the same way. Not hoarding but things being in disarray and clutter. Now I see it in my children and grandchildren and I know it's neurological.One of my sons lined all his toys a certain way and would cry if you moved them.

Pamela Oglesby (author) from Sunny Florida on October 15, 2020:

Hi John,

I fully agree about the complexity of these various intellectual disabilities. I think there is a great deal that the scientist simply don't know at this time.

Thank you for sharing so much of your personal experience. Your children are a great example of success despite some learning problems when they were younger. I think the time when we are maturing probaby helps in some cases, although is just my personal view. I appreciate your very generous comments.

John Hansen from Gondwana Land on October 15, 2020:

A very interesting article Pamela. Intellectual Disabilities are very complex and have so many different levels of severity. For instance my daughter had learning disabilities due to having to take constant asthma medication from a very young age. In early high school one cruel Teacher said she should aim towards being a social butterfly as she will never make it academically.

But my daughter was determined and studied so hard she graduated from high school with pass marks and is now an artist in various mediums.

On the other hand I have two sons who were classed as ‘gifted’ students, and my youngest son had some learning disabilities, ADHD, and slight autism, but now, as an adult, the most successful of all my children.

Pamela Oglesby (author) from Sunny Florida on October 15, 2020:

Hi Rosina,

I think autism is much more common now than it once was and I really don't know why. I'm glad you enjoyed the article and your comments are much appreciated.

Rosina S Khan on October 15, 2020:

This was an interesting article on facts about intellectual abilities. Yes, I have heard of many cases that those who have autism sometimes excel in music, singing, or painting. Thank you, Pamela, for such an informative and helpful article.

Pamela Oglesby (author) from Sunny Florida on October 15, 2020:

Hi Ann,

I agree that these diseases probably overlap. There are so many aspects and I found it difficult to narrow down this topic due to the vast amount of information aboutl all of these disease

I have a cousin who is dyslexic and I think he has ADHA also. It seems all of these disorders are more common now. I appreciate your very nice comments, Ann. Stay safe and healthy.

Pamela Oglesby (author) from Sunny Florida on October 15, 2020:

Hi Bill,

I find autism very interesting also due to the various manifestations. I know of at least two people that I think probably have very mild autism. One is a little boy and they won't get him tested as they think he will be labeled as autistic and they don't want that. He makes straight A's in school but still poops his pants sometimes. LOL

I'm glad you enjoyed this article as I found it difficult to write due to the vast amount of information. Thank you for your comments and I hope your Thursday is spectacular also.

Ann Carr from SW England on October 15, 2020:

This is an interesting and comprehensive overview. When teaching dyslexics, I came across several who also had Autism/Asperger's as well as ADHD. It seems these overlap quite frequently; that would be an interesting study in itself!

You always set out your medical facts clearly, in a fashion easy to follow for the layman (or should I say layperson?!). You also cover every angle and your articles are a pleasure to read.


Bill Holland from Olympia, WA on October 15, 2020:

Autism is a fascinating disorder, is it not? There are so many different manifestations along the spectrum. I was watching a tv series on Netflix about autism, and it was riveting.

Anyway, that was a long-winded way of saying I really enjoyed your article. :) But then, I always do!

Have a spectacular Thursday, Pamela.

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