Features of Intellectual Disability, and Interventions


Mr. Basavaraj S Hukkeri

Assistant Professor

D. Y Patil college of Nursing, Kolhapur

Intellectual disability (ID), once called mental retardation, is characterized by below-average intelligence or mental ability and a lack of skills necessary for day-to-day living. Mental retardation refers to significantly sub average general intellectual functioning resulting in or associated with concurrent impairment in adaptive behavior and manifested during the development period

What is intellectual disability?

Intellectual disability has limitations in two areas. These areas are:

Intellectual functioning (IQ): this refers to a person’s ability to learn reason, make decisions, and solve problems.
Adaptive behaviors: is defined as the degrees with which the individual meets the standards of personal independence and social responsibility expected of his age cultural group.


Intelligent quotient is the ratio between Mental Age (MA) and Chronological Age (CA).

Intelligence quotient is measured by an IQ test. The average IQ is 100.

Classification of Mental Retardation based on Intelligent Quotient









Profound(Life support )


To measure a child’s adaptive behaviors, a specialist will observe the child’s skills and compare them to other children of the same age. Things that may be observed include how well the child can feed or dress himself or herself; how well the child is able to communicate with and understand others; and how the child interacts with family, friends, and other children of the same age.

Intellectual disability is thought to affect about 1% of the population. Of those affected, 85% have mild intellectual disability. This means they are just a little slower than average to learn new information or skills. With the right support, most will be able to live independently as adults.

Signs and Symptoms

Generally speaking, the symptoms of mental retardation include delays in oral language development, deficits in memory skills, difficulty learning social roles, difficulty with problems solving skills, decreased learning ability or an inability to meet education demands at school, failure to achieve the markers of intellectual development and a lack of social inhibition.

However, symptoms of mental retardation will vary depending on the condition’s severity. For instance, while signs of mild retardation (i.e., those with IQs of about 52 to 79) may include a lack of curiosity and quiet behavior, signs of severe mental retardation (i.e., those with IQs of about 20 to 35) may include infant-like behavior throughout the patient’s life, and those with profound mental retardation (i.e., IQs of 19 or below) are likely to have limited motor and communication skills and require lifelong nursing care.

The symptoms of mental retardation are broken out by the level of the condition below.

Mild intellectual disability: From birth to age six, these children are able to develop social and communication skills, but their motor skills are slightly impaired. In late adolescence, they can usually read at a sixth-grade level. They are typically able to develop appropriate social skills, and adults can often work and support themselves, though some of these individuals may require assistance during times of social or financial stress.
Moderate intellectual disability: Children with this condition who are six years old or younger can talk and communicate, but usually have poor social awareness. Their motor coordination is fair, and adolescents can learn some occupational and social skills. Adults can sometimes support themselves and hold down a job, though they often require guidance and assistance during stressful periods.
Severe intellectual disability: Young children with this condition have limited speech abilities, though they can usually say a few words. Their motor coordination is mostly poor. While adolescents can communication with others and can learn simple habits, they typically require lifelong guidance and assistance with daily activities.
Profound intellectual disability: Young children with this level of mental retardation have very little motor coordination of often require nursing care, which can last a lifetime. Adolescents have limited motor and communication skills.


Intellectual disabilityaffects about 1% to3% of the population. In India, 5 out of 1000 children’s are MR (The Indian Express, 13th March 2001) Causes of intellectual disability can include:

Infections (present at birth or occurring after birth)
Genetic Factors (such as Down syndrome)
Environmental (Child Abuse)
Metabolic (Wilsons Disease)
Nutritional (malnutrition)
Trauma (before and after birth)
Unexplained (this largest category is for unexplained occurrences)

To meet the criteria for the diagnosis of Mental Retardation, three areas must be considered.

Onset must occur before 18 years of age.In addition, the person must have
Below average general intellectual functioning.General intellectual functioning is defined by the intelligence quotient (IQ) obtained by assessment with one or more of the standardized, individually administered intelligence tests. The choice of testing instrument and interpretation of results should take into account factors that may affect test performance, such as sociocultural background, native language and associated communication, and motor and sensory handicaps. Specialized tests may be used to measure other aspects of development. Intellectual impairment is categorized by four degrees of severity. These classifications suggest the types of interventions that would be appropriate and offer clues as to long-term outcome.

Mild retardation:Mild retardation: IQ level 50-55 to approximately 70 (85% of people with mental retardation are in this category)

Moderate retardation:IQ level 35-40 to 50-55 (10% of people with mental retardation)

Severe retardation:IQ level 20-25 to 35-40 (3 – 4% of people with mental retardation)

Profound retardation:IQ level below 20 or 25 (1 – 2% of people with mental retardation)

Significant limitations in adaptive functioningin at least two of the following skill areas: communication, self-care, home living, social/interpersonal skills, use of community resources, self-direction, functional academic skills, work, leisure, health and safety.
Genetic counseling: screening during pregnancy
Social Nutrition programs
Preventing exposure to lead, mercury, and other toxins reduces the risk of disability.
Infectious diseases: For example, rubella syndrome can be prevented through vaccination. Avoiding exposure to catfeces that can cause toxoplasmosis during pregnancy helps reduce disability from this infection.

What about School?

Early intervention programs are essential to maximize the children’s potential development. This necessitates early recognition and referral. Teachers have opportunity to evaluate children’s in school. Some of these skills include:

communicating with others.
taking care of personal needs (dressing, bathing, going to the bathroom).
health and safety.
home living (helping to set the table, cleaning the house, or cooking dinner).
social skills (manners, knowing the rules of conversation, getting along in a group, playing a game).
reading, writing, and basic math and as they get older, skills that will help them in the workplace.

Supports or changes in the classroom (called adaptations) help most students with mental retardation. Some common changes that help students with mental retardation are listed below under “Tips for Teachers.” The resources below also include ways to help children with mental retardation.

Tips for Parents

Learn about mental retardation. The more you know, the more you can help yourself and your child. See the list of resources and organizations at the end of this publication.
Encourage independence in your child. For example, help your child learn daily care skills, such as dressing, feeding him or herself, using the bathroom, and grooming.
Parents are taught behavior modification techniques to decrease to eliminate problematic behavior.
Give your child chores. Keep his/her age, attention span, and abilities in mind. Break down jobs into smaller steps. For example, if your child’s job is to set the table, first ask him/her to get the right number of napkins. Then have him/her put one at each family member’s place at the table. Do the same with the utensils, going one at a time. Tell him/her what to do, step by step, until the job is done. Demonstrate how to do the job. Help her when she needs assistance. Give your child frequent feedback. Praise your child when he or she does well. Build your child’s abilities.
Find out what skills your child is learning at school. Find ways for your child to apply those skills at home. For example, if the teacher is going over a lesson about money, take your child to the supermarket with you. Help him count out the money to pay for your groceries. Help him count the change.
Find opportunities in your community for social activities, such as scouts, recreation center activities, sports, and so on. These will help your child build social skills as well as to have fun.

Tips for Teachers

There is now an increase use of more specialist teaching and variety of innovative procedures for teaching language and other methods of communication.

Hints for successful skill training

Give the student immediate feedback.
Divide each training activity into small steps and demonstrate.
Start the training with what the child already knows and then proceed to the skill that needs to be trained.
Reward his effort even if the child attains near success.
Give the training regularly and systematically.
Use training materials which are attractive, appropriate and locally available.
Environmental supervision
Programs that Maximize Speech, language, social, psychomotor, cognitive and occupational skills.
Ongoing Evaluation.
Parental counseling and supportive psychotherapy.
Behavior management.


Townsend M, Psychiatric Mental health Nursing, 6th ed. New Delhi: Jaypeee Brother Publications ; 2013:chap 4.
The Arc of the United States American Association on Mental Retardation (AAMR)