The exact definitions of terms such as 'lunatic', 'imbecile', 'idiot' and 'feeble-minded' are extremely problematic. According to the 1881 Census Report;
No accurate line of demarcation can be drawn between the several conditions indicated by these terms. Speaking generally, however, the term idiot is applied in popular usage simply to those who suffer from congenital mental deficiency, and the term imbecile to persons who have fallen in later life into a state of chronic dementia. But it is certain that neither this nor any other definite distinction between the terms was rigorously observed in the schedules, and consequently no attempt has been made by us to separate imbeciles from idiots. The term lunatic also is used with some vagueness, and probably some persons suffering from congenital idiocy, and many more suffering from dementia, were returned under this name.
Considering that householders, who could be illiterate, were being asked to give information about medical disabilities without any definition of the terms being used the answers should be treated with caution. Also they would be unwilling to admit that anyone in the family had medical disabilities.
When ‘feeble-minded’ was substituted for ‘idiot’ in the 1901 census the number of persons recorded with mental disability rose markedly, because, apparently the former term was considered much less derogatory than the latter.
Some terms do have a formal definition in the UK although they are no longer used :
Term Idiot IQ 0 to 25 Modern term Severe learning disability
Imbecile 25 to 50 Moderate learning disability
Feeble minded (moron) 50 to 70 Mild learning disability
Those with an IQ of less than 50 usually need care throughout life and are unlikely to educable in the formal sense.
Stan
