Intellectual Disability: Definition And Types

People with intellectual disabilities have less cognitive resources or less developed cognitive resources than would be expected given their chronological age. This increases the difficulty of learning, in addition to requiring a greater effort to communicate in some contexts and with certain messages. This type of disability is usually identified before the age of 18 and affects 1% of the world’s population.

Importantly,  intellectual disability is not a mental illness, but a developmental disorder. All people with this type of disability are like us: they have their own dreams, interests, tastes and preferences. In this sense, it is important not to stigmatize the condition and, for that, what could be better than knowing a little more about it?

Intellectual Functioning and Adaptive Behavior

Intellectual disability can be of different degrees and each one of them implies specific difficulties. It manifests with problems with reasoning, planning, problem solving, abstract thinking, and learning, all due to  slow and incomplete acquisition of cognitive skills.

Their adaptive capabilities can also be very limited, both conceptually and socially and practically. Therefore, their ability to express themselves verbally or their read-write are poorly developed, as well as their sense of responsibility or their self-esteem.

Faced with daily activities, such as hygiene, personal care or preparing food, they may have a variable level of autonomy depending on the degree of delay. In instrumental or mechanical activities this variability also exists.

Impact on health and social interactions

This inability  may be accompanied by certain changes related to physical and mental health. All of this in turn can affect the rest of the dimensions.

Some syndromes that are associated with intellectual disability are: Rett, Dravet, Prader-Willi, Down, Asperger, and Fragile X syndrome. It is also more prevalent in cases of diseases such as obesity, diabetes, HIV or STDs, and dementia.

Communication, interaction or social participation are also affected. Intellectual and adaptive limitations make it impossible for this person to participate in the life of their community in a normal way. This  affects all your areas: home, study, work and your leisure time.

The role of the intelligence quotient

The intelligence quotient, by itself, is not a sufficient criterion to make a diagnosis of intellectual disability. In addition to quantitatively defining intelligence, it is necessary to make  a deeper assessment of a person’s intellectual functioning.

IQ is understood as  the relationship that exists between the person’s mental age and chronological age. The first refers to the age that corresponds to him according to his intellectual development. That is, how much it yields intellectually compared to the average level of your reference group. The chronological age is the biological one.

A certain intellectual disability is considered to  exist if the intellectual quotient is less than 70.  The other extreme, giftedness, is diagnosed when the index is above 130. It is precisely the IQ that serves to classify the degree of this disability.

Types of intellectual disability

According to the DSM-IV, it is classified as mild, moderate, severe and profound.

Light (IQ 50-55 to 70)

85% of people with disabilities have a mild disability.

• Conceptual domain:  low impact on abstract thinking, functional skills, cognitive flexibility and short-term memory.
• Social domain: immature social interactions, which increase the risk that the disabled person will be manipulated.
• Practical domain: it  is necessary that they have supervision, guidance and assistance when carrying out tasks of their daily life. This help is very important, especially in stressful situations.
• They often do not differentiate from other children without this disability until they are older.

Moderate (IQ 35-40 to 50-55)

10% of people with disabilities have a moderate disability.

• Conceptual mastery: require continuous assistance to complete everyday activities. Also, sometimes it is necessary that other people assume some of their responsibilities. These are people who, with moderate supervision, are able to acquire skills for their own personal care. They can perform jobs that do not require qualification or semi-qualification, but always under supervision.
• Social domain:  when communicating verbally, their language is less rich and complex than that of people without disabilities. This makes them unable to correctly interpret some social keys and having trouble creating new relationships.
• Practical domain:  with continued support and instrumentation, they can develop certain skills and abilities.

Severe (IQ 20-25 to 35-40)

3% – 4% of people with disabilities have severe disability.

• Conceptual domain:  very limited, especially with numerical concepts. Support is important, constant and in many areas.
• Social domain:  its oral language is very elementary, its sentences grammatically simple and its vocabulary very limited. Your communications are very basic, limited to the here and now.
• Practical domain:  supervision must be constant in all the tasks they need to perform in daily life.

Deep (IQ 20 – 25)

Even though they are a minority (1% – 2%),  most of these people have an identified neurological disease  that explains their disability.

• Conceptual domain:  only consider the physical world and symbolic processes. With instructions, they can acquire certain visuospatial skills, such as ticking. The associated motor and sensory difficulties often prevent the functional use of objects.

• Social domain:  poor understanding of verbal and gestural communication. His way of expressing himself is very basic, simple and mostly non-verbal.
• Practical domain:  the patient is totally dependent in all areas. Only if there are no motor or sensory affectations will you be able to participate in certain basic activities.

The role of institutions is essential if we are to create an easier and more accessible environment for people with intellectual disabilities. If not, other environmental limitations will be added to the limitations that these people already have. In any case,  what we must never forget is that the person is before incapacity. Someone with feelings, just like the rest of us, someone with dreams, just like the rest of us, and someone with a lot of things to offer to others.