Types of intellectual disability (and characteristics)

Oligophrenia, mental retardation, intellectual disability... all these words refer to the same concept, with the that we refer to those people who have less cognitive resources than expected due to their age chronological. People with any of the types of intellectual disability.

This type of disability generally causes severe difficulties in adapting to the environment, unless they are given a sufficient level of help. But intellectual disability is not unique and homogeneous in all people who suffer from it, but we can find different types or degrees depending on the degree of functional impairment and level of IQ.

The normal distribution and intelligence

Intelligence is a construct that refers to the ability of the individual to be able to adapt to the environment and resolve the situations you encounter. Regardless of how it is viewed within the multiple theories about it, different people will have organized in different ways and their mental capacities will be affected for various reasons and variables. Each of us has a specific and distinctive degree of ability or capacity in the different fields and abilities, including the ability to solve problems and adapt to the environment.

To assess the intelligence level of the population the IQ level has been traditionally used, understood as the relationship between mental age and chronological age of the individual to be assessed. Taking into account that there is a great variability in the scores reflected by the population as a whole, it is It is necessary to bear in mind that it will always be expected that there will be a certain dispersion of scores around the half. This expected dispersion is conceptualized as a standard deviation.

Statistically, intelligence follows a normal distribution. That is, if we score the cognitive abilities of a population with a Inteligence test, a vast majority of people would have scores very similar to each other while few individuals would have scores far removed from the majority. People with these types of scores, far from the majority, could either score higher or lower.

Having set the mean IQ at a value of 100 and the standard deviation being 15, Values ​​that are at a distance of at least two deviations are considered normative typical. If these two deviations are given above, we would be talking about giftedness, while if values ​​are given two deviations below the mean we will be talking about an intelligence level corresponding to intellectual disability.

• Related article: "Intelligence: the G Factor and Spearman's Bifactorial Theory”

Types of intellectual disability

Intellectual disability is understood as a condition in which the people who suffer from it have severe limitations and deficiencies in intellectual functioning, having problems with reasoning, planning, problem solving or learning.

In addition, these people have deficiencies in adaptation to the environment, needing help in one or more dimensions of human functioning so that their daily life is not limited in their personal autonomy and social participation. It is classified as a neurodevelopmental disorder, and these difficulties must be observed during development.

However, this is not a totally homogeneous category, and that is why different types of intellectual disability have been established according to the degree to which they deviate from the average.

Different degrees of disability

Cognitive skills are important to be able to respond efficiently to the demands of the environment. Thus, people who have a reduced capacity in these types of skills will find it difficult to cope with the situations that appear throughout their lives.

Depending on the level of difficulty that these people find in their day-to-day life and the IQ level reflected by intelligence tests, the existence of various groups, types or degrees of intellectual disability has been considered.

However, it must be taken into account that the degree of IQ is not an absolute measure, but a relative one; It always depends on a reference group, since the IQ indicates the position that the person occupies in the distribution of scores obtained. Therefore, by changing the reference group a score may be within the normal range of intelligence or in what is considered to be intellectual disability. IQ indicates individual differences between people, but to measure a person's true cognitive abilities exactly, there are other tools and methods.

1. Mild

Mild or mild intellectual disability is considered to be that possessed by people with an IQ that is between 50 and 70, corresponding to two standard deviations below the population mean. Most people with intellectual disabilities (approximately 85%) are at this level.

People with this degree of intellectual disability mainly have a delay in the cognitive field and a slight affectation in the sensorimotor. The learning capacities are slightly behind, but they can remain in the educational system, train and carry out a professional activity adequately. They are able to read, write and perform calculations, although they usually require a longer learning period than others. In fact, it is possible that during preschool there are no great differences with their peers.

Some problems can be observed in the memory, executive functions and abstract thinking. Their communication and social skills can be good, although they tend to have some difficulty detecting social cues and regulating their emotions and behavior. They are mostly autonomous people, requiring social guidance in specific situations, and help with legal, economic or child-rearing issues. Although they need support, their adaptation to the environment is normally satisfactory.

2. Moderate

In this degree of intellectual disability the difficulties are greater. At an educational level, they are usually able to benefit from specific job training, generally in order to carry out low-skilled jobs with supervision. They can have autonomy in self-care and movement.

The conceptual abilities of these subjects develop very slowly, with a great difference with respect to the peer group. They often need help when tasks require processing complex concepts. Their communication is efficient socially, although not very complex. The subject is able to establish relationships with the environment and make new links with people outside the family.

Although they may have trouble following social conventions, they generally adapt well to community life, especially with supervision. The individual can take responsibility for their own decisions and participate in social life, albeit with support and a long learning period.

People with a moderate degree of intellectual disability usually reflect an IQ ofbetween 35-50.

3. Serious

With an IQ between 20 and 35, the problems for people with this level of disability are generally of great importance, requiring assistance and continuous supervision. Many of them present neurological damage.

At a conceptual level, the abilities of people with this degree of intellectual disability are reduced, having little understanding of reading and numerical concepts. Communicationally language is possible but limited, focusing on the present and being frequent that they use holophrases or single words. They understand simple oral and gestural communication, being the relationship with loved ones a source of joy.

In day-to-day activities, these subjects always need to be supervised and cared for, depending on help and custodians. They can learn to speak and perform simple tasks. Their adaptation to the community may be good unless they have some other associated disability. Acquiring skills is possible, needing constant help and a long learning process. Some of them self-harm. At the legal level, they are considered incapable of making their own decisions.

4. Deep

The highest degree of intellectual disability and also the rarest, people with this level of disability have an IQ below 20. They need to be constantly cared for, having very few options unless they have a very high level of help and supervision. Their survival rate is generally low.

Most of them have great difficulties and other serious disabilities, as well as great neurological problems. At a conceptual level, these people use take into account mainly physical concepts, suffering from serious difficulties in using symbolic processes. The use of objects for self-care, work or leisure is possible but it is frequent that other alterations prevent giving them a functional use. At the sensorimotor level they are very limited, as well as at the communicative level.

Regarding the communication and social sphere, they can understand instructions and gestures, but they have to be simple and direct. Emotional expression occurs primarily through direct non-verbal communication, without symbolism. They enjoy being with people they know. On a practical level, the subject will have dependency for most activities, although they can help in some activities, enabling them to participate in the daily life of the home and society.

The need for help

As a conclusion to this article, it is relevant to mention that a person It is only disabled to the extent that it does not have the tools to adapt to the environment, due to their difficulties and the lack of support to help them solve them. In this sense, intellectual disability is no exception. We cannot limit ourselves to pointing out that someone has an intellectual disability and limiting the problem to the individual; society has a lot to say when it comes to changing the living conditions of these vulnerable people.

It must work from the different disciplines (psychology, judicial field, legislative field, education and social assistance, among others) with so that these people and the people who care for them can participate actively in the social life of the community, establishing bridges between the capacities of each individual and what society can offer and demand through the granting of specific aids and functional.

Bibliographic references:

• American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders. Fifth edition. DSM-V. Masson, Barcelona.