Donate Now Through!

Visually Impaired?

Change to Black and White

Text Size:

minus plus
megaphone Hear this text

Basic Information about Developmental Disabilities and Communication

Excerpt from BCACL booklet: “Restorative Justice and People with Developmental Disabilities”

Printable version (pdf)

What is a Developmental Disability?

A developmental disability is a life-long condition that manifests at birth or shortly thereafter, where people grow and develop more slowly than others because of limitations in intellectual functioning and adaptive functioning. Individuals may have difficulty understanding abstract concepts or adapting to some of the demands of daily life.

Causes of Developmental Disabilities

There are over 200 causes of developmental disabilities, and in some cases, the cause is never known. A developmental disability can be caused by different kinds of trauma to the developing brain and nervous system. However, developmental disabilities are generally attributed to the following factors:

  • Genetic Factors such as abnormal genes that are inherited
  • (Fragile X syndrome), and errors when chromosomes combine (Down’s syndrome)
  • Early influences during mother's pregnancy such as alcohol ingestion and contracting of rubella or other infectious diseases
  • Problems during birth such as premature delivery, or trauma/anoxia
  • Problems soon after birth or in childhood which include head injuries and certain childhood diseases
  • Environmental Factors like poverty, neglect, deprivation, malnutrition

Developmental Disabilities and Mental Illness are not the same

Developmental Disabilities are not the same as mental illnesses, although in some cases, a person may have both. It is important to recognize the differences between the two conditions in order to be able to interact appropriately with individuals.

Mental Illness

Developmental Disability

Refers to a person's thought
processes, moods, emotions

Refers to below-average ability to learn and to process information.

Can occur at any time in a
person's life

Occurs before a person reaches adulthood.

Has nothing to do with IQ.

Refers to below average IQ.

May be temporary, cyclic, or episodic, and may be curable.

Is lifelong. There is no cure.

Services involve therapy and
medication treatment by

Services involve training
and education, not

Diagnoses such as Paranoid
Schizophrenia, Personality disorder, (Manic) depression.

Is NOT a diagnosed

May be very socially competent.

Usually involves impairments in social adaptation.

May vacillate between normal and irrational behaviour.

Usually behaves rationally at his/her operational level

Some ways that a person with a developmental disability may speak, act or look:

There is a wide range of developmental disabilities and people do not share a consistent set of characteristics. However, there are some ways that one may speak, look, or act:


  • have difficulty answering questions or following instructions
  • short attention span, easily distracted
  • difficulty describing facts or details of the incident
  • may appear confused about who is responsible for what action
  • limited memory or impaired recall
  • limited vocabulary
  • may mimic or imitate the way others communicate
  • act upset or try to run away
  • may not understand what is being said, but pretend to understand
  • say what he or she thinks others want to hear
  • may always refer to a caregiver, family members or support person in describing his or her activities/daily routine

Observations and Task Performance:

  • may be inappropriately dressed for the weather
  • generally has difficulty with reading and writing
  • appears to be eager to please and easily led
  • may appear overwhelmed by the presence of people in authority (e.g. judge, police or Elder).

Communicating with a Person with a Developmental Disability

People with developmental disabilities are able to communicate effectively, although they may take more time or need some accommodation in conveying their message. In having a conversation, use plain language.  It is important to keep in mind that a person with a developmental disability tends to think in concrete terms and may have a limited memory.

Always remember to:

  • Make sure that you have the person's attention
  • Speak directly to the person (even when a support person is present)
  • Speak slowly and clearly
  • Take time in asking a question and waiting for an answer
  • Keep instructions simple and allow ample time for the person to comply

In asking questions:

  • Break down complex questions into several simple questions and ask them one at a time
  • Ask open-ended and free recall questions instead of "yes/no" questions (e.g. "What did you see?" instead of "Did you see the man run toward you?")
  • Ask the person if he or she wants the question to be repeated, if no reply is forthcoming
  • Repeat the question or phrase it in a different way if you suspect that the person may not have understood it (asking the question repeatedly is better than interpreting the response inaccurately)
  • Use points of reference when asking for information regarding time and sequence of events, and use landmarks when asking about locations
  • When in doubt, try asking the same question in a different way to confirm earlier responses (or seek validation from a different source)
  • Use words of encouragement, and if the interview is not progressing very well, ask if the person needs a break
  • Bear in mind that it is possible that a person with developmental disabilities may agree with something even if it's not the truth because he or she (1) feels that that is what the interviewer wants to hear, (2) wants to hide his or her inability to read/understand/recall, (3) feels that such an answer would not require further elaboration, and (4) doesn't want to appear "stupid".
  • Some people may require the help of a support person or advocate when communicating, while some may require different communication aids like communication boards or pictures.

This is an excerpt from BCACL booklet: “Restorative Justice and People with Developmental Disabilities”