What are Developmental Disabilities?

The more you understand about developmental disabilities, the more you appreciate these remarkable people. Here are some of the basics.

What are Developmental Disabilities?

The more you understand about developmental disabilities, the more you appreciate these remarkable people. Here are some of the basics.

Developmental Disability: A Definition

Developmental disability is the broad term used to describe a range of conditions that affect physical and/or mental functioning. For a condition to be considered a developmental disability, the manifestations or symptoms of the condition must be present in childhood years and expected to be present for life. Most developmental disabilities are present at birth and may be identified early in life, although some developmental conditions may not be recognized until after age three. Conditions that arise or are detected in adolescent or adult years are not considered developmental disabilities.

Common Developmental Disabilities

A variety of conditions are classified as developmental disabilities. Among the most common are intellectual disability, autism spectrum disorder, Down syndrome, and cerebral palsy.

What Causes Developmental Disabilities?

A number of things can cause a developmental disability, but all of them re related to the development of the brain and nervous system. In many cases, the direct cause is unknown. Sometimes healthy and typically functioning parents can have a child born with a developmental disability.  Other known causes of developmental disabilities include:

  • Drug or alcohol abuse during pregnancy
  • Genetic disorders such as Down Syndrome or Fragile X syndrome
  • Accidents during infancy or childhood that cause trauma to the brain
  • Malnutrition
  • Infectious diseases
  • Abuse and neglect

While the direct cause may not be known in many cases, the manifestation of a developmental disability is always related to the brain, or parts of the brain, not developing as expected.

Characteristics of Developmental Disabilities

All children develop differently; however, there may be particular speech and language, communication, physical, motor, social, and behavioral symptoms to watch out for. In general, children with developmental disabilities acquire skills at a slower pace (or not at all) than other children of similar age. We share information about what to look for on our Developmental Milestones page.

What Are Behavioral and Intellectual Disabilities?

A behavioral disability is often associated with an intellectual disability or autism spectrum disorder, but may also exist in a child without these conditions. Behavioral disabilities are externalizing behaviors that occur at levels of frequency and severity that far exceed those of other children of similar age. These behaviors might include physical aggression, defiance, tantrums, impulsivity, lying, refusals, and oppositionality. Whether or not a child has a behavioral disability is usually determined by whether the behaviors interfere with the child’s daily living functioning (e.g. going to school, family relationships, ability to make and maintain friends, etc.). If a child’s behaviors interfere with these typical functions, there may be a behavioral disability present. Common behavioral disabilities include oppositional defiant disorder, conduct disorder, and attention-deficit hyperactivity disorder (ADHD).

An intellectual disability may occur alongside a behavioral disability and/or autism spectrum disorder. An intellectual disability is confirmed when a child’s tested/measured IQ functioning is at 70 or below (an average IQ ranges from 85 to 115) and there are clear deficits in his/her adaptive behavioral skills (self-help, safety, communication, social). Children with IQs measured below 70 but have average or even below average adaptive behaviors do not qualify for a diagnosis of intellectual disability.

Put the Person First

When talking about people with disabilities, always put the person first. For example, say “a child with autism” rather than “an autistic child.” Say “a child with challenging behaviors” rather than “a bad kid.”

Be Your Kind, Respectful Self

It is most respectful to interact with a child with disabilities mostly the same way you would with a child without disabilities. Talk directly to them, even if they cannot talk. Greet them respectfully. Look them in the eye when you talk, even if they look down. Ask them questions even if you think they don’t understand. Reach out to shake their hand, even if they can’t shake back. Ask them permission to talk to them or talk to their parents, even if they don’t have the capacity to give permission.

With this in mind, always be sensitive. For example, if a child is in a wheelchair, bend down on one knee so that you look them directly in the eye when you talk to them. Be sensitive to using quick or aggressive movements or approaches. Provide direction and structure when necessary (e.g., “Now we are going to go to that room over there. Is that ok with you? Do you need my help to get there?”). Always ask permission to touch a child with a disability. Many children are sensitive to touch, bright lights, loud noises, and other external stimuli.

When in doubt, ask the person’s caregiver the best way to interact with them. Want to know more or get more involved? Check out our training opportunities.

Raise Your Voice

People with developmental disabilities need more than the love and support of their families and friends. They also need strong voices to speak for them out in the world. You can help. Damar can show you how.

Concerned About a Child?

Are you worried about a child you think may have a disability? Know that you’re not alone. If you think it’s time to find out for sure, Damar can help. We’ll help you learn where to start—and support you every step of the way through diagnosis and, if necessary, a unique treatment plan.

What Conditions are Not Developmental Disabilities?

Any condition that is first detected or manifested in the adolescent years or young adult years is typically not considered a developmental disability. For example, if a teenager is struck by a car and is unable to communicate and or becomes disabled, this is typically not considered a developmental disability. An adult diagnosed with ADHD is not considered to have a developmental disability (even if the symptoms were present in childhood and not identified).

What Are Some Myths About Disabilities?

There are many. Some include that children with disabilities do not notice things in the environment and/or are not affected by positive or negative events as much as non-disabled children; that they don’t experience love or attachment; that they can’t become independent; that they don’t have sexual feelings and are not sexual; that children with disabilities are all the same; that they’re burdens to their families; that their behaviors are nonsensical and have no meaning; that they should not be part of our communities; that they cannot work at all; that they do not have feelings; and that they are not as valuable or precious as other children.

It’s a heartbreaking list of untruths. Children with disabilities are as remarkably human as any of us, with challenges many of us could never imagine. 

What’s it like to live with a disability?

Frequently Asked Questions

What happens after an autism diagnosis? What services are available? What do you do next? We have answers to these questions and many others.


Have questions? Looking for support? Get in touch with us to learn more.