People with intellectual disability form one of the largest single disability groups in a community. Intellectual disability refers to a general slowness to learn and function within society, and the identification of intellectual disability is usually based on an assessment of a person’ s performance in a variety of tests. An individual’ s level of performance, as assessed, can change with time and circumstances. On occasions, an intellectually disabled person may perform better than at other times. Evidence for this inconsistent level of performance comes from modern research and practice which have shown that with skilled training and opportunity for development, people with intellectual disability have much greater potential for acquiring skills and for participation in community life than previously had been thought possible. 

In many western societies, five categories of intellectual disability have traditionally been used in order to indicate the perceived degree of difficulty an individual has in learning. All five may occur in either children, adolescents or adults, and show as mild, moderate, severe, profound or multiple intellectual disability. However, undue reliance on such categories and the consequent “pigeonholing” of individuals into one of the five categories can result in failure to provide the opportunities for each person to develop. 

For the majority of intellectual disabilities, there is no identifiable cause but there are some causes that are well documented. They include: brain damage at birth due to lack of oxygen-prolonged labor during childbirth; brain damage before birth due to factors such as rubella drug or diet-related problems; damage after birth due to illnesses such as encephalitis or accidents; hereditary defects in the genes, abnormal chromosome count resulting in, for example, Down Syndrome. 

Like everyone else, people with an intellectual disability need a rewarding job, a satisfying place to live and a good social life. But they may need extra support to achieve these things. Good support services are based on the principle of normalization-which means enabling people to be part of the community like everyone else. In turn, normalization needs to be well-integrated into the community, in order to be effective. Some of the services needed include assessment centers, training for employment and support to keep jobs once they get them, residential accommodation that is homelike. For children, early education and school education appropriate to the child’ s needs are essential. Without a strong community-based system of care, the intellectually disabled run the risk of becoming a huge under class as in the United States, where thousands of intellectually disabled are homeless because of the American policy of deinstitutionalization. 

With the introduction of the intellectually disabled into communities, there is a need to promote awareness of communication. Although many people may have little experience in talking with an intellectually disabled person, and anticipate great difficulty in communication, there are common guidelines that can simplify the interaction. Firstly, it is useful to remember that people with disabilities have feeling sad can usually understand what is said, even though they sometimes may take longer to respond. Speaking in the same friendly manner as you would to anyone else, and using straightforward language and uncomplicated sentences, is also recommended. Being prepared to wait a little longer for replies during a conversation with an intellectually disabled person, would undoubtedly benefit the exchange. Above all, it is suggested not to talk about the person with someone else within their hearing. Ultimately, the idea is to encourage intellectually disabled people to do things for themselves.