Language and Definitions

A Glossary of Historical Terms

The UK Mental Deficiency Act of 1913 categorised learning disabled people as follows:

  • Idiots – Persons in whose case there exists mental defectiveness of such a degree that they are unable to guard themselves against common dangers such as traffic or fire. Today these people would be described as having a profound to severe learning disability.
  • Imbeciles – Persons in whose case there exists mental defectiveness which, though not amounting to idiocy, is yet so pronounced that they are incapable of managing themselves and their affairs or, in the case of children, of being taught to do so. Today these people would be considered to have a severe learning disability.
  • Feeble minded – Persons in whose case there exists mental defectiveness which, though not amounting to imbecility, is yet so pronounced that they require care, supervision and control for their own protection or the protection of others. Or, in the case of children, that they appear to be permanently incapable by reason of such defectiveness of receiving proper benefit from instruction in ordinary school. Today these people would probably be considered to have a moderate learning disability.
  • Moral defective – Persons in whose in whose case there exists mental defectiveness, coupled with strong vicious and criminal propensities and who require care, supervision and control for the protection of others. These people included unmarried mothers.

Other terms in common use in the past


  • Cretin was the oldest term, from the French, referring to those with both physical and intellectual incapacity.
  • Moron referred to an adult with the intellectual development similar to an 8 to 12 year old child.  Today this person would probably described as having a mild to moderate learning disability.
  • Retarded came from the Latin retardare, meaning to make slow, delay, keep back. Mental retardation was a general term which covered all levels of learning disability.
  • Mongolism was a medical term used to identify someone with Down’s syndrome.

Terms in Use Today

Today the words, mild, moderate, severe and profound are used to describe the degree of learning disability.

In the recent past some people might have said a learning disabled person. However we would say a person with a learning disability. The person always comes first then the disability.

The media often confuse a mental health problem with a learning disability.
A learning disability is not a disorder or a disease but a life-long condition.

People are sometimes described in the media as being a Down’s sufferer or an Autism sufferer. This is misleading as the word suffering implies a disease. Generally no one is suffering.

The Euphemism Treadmill

Professor Steven Pinker, psychologist and cognitive scientist, invented the expression euphemism treadmill to describe how words that come into use to replace those that are offensive eventually become offensive themselves.

What is a Learning Disability?

The following is reproduced from the Mencap website:

A learning disability is a reduced intellectual ability and difficulty with everyday activities – for example household tasks, socialising or managing money – which affects someone for their whole life.

People with a learning disability tend to take longer to learn and may need support to develop new skills, understand complex information and interact with other people.

The level of support someone needs depends on individual factors, including the severity of their learning disability. For example, someone with a mild learning disability may only need support with things like getting a job.

However, someone with a severe or profound learning disability may need full-time care and support with every aspect of their life – they may also have physical disabilities.

People with certain specific conditions can have a learning disability too. For example, people with Down’s syndrome and some people with autism have a learning disability.

Learning disability is often confused with dyslexia and mental health problems. Mencap describes dyslexia as a “learning difficulty” because, unlike learning disability, it does not affect intellect. Mental health problems can affect anyone at any time and may be overcome with treatment, which is not true of learning disability.

It’s important to remember that with the right support, most people with a learning disability in the UK can lead independent lives.