The microcephaly/oligophrenia is mentally retarded. The term comes from the Greek language and means "mental deficiency".
Oligophrenique syndrome is the name which, before, was given to the psychological pathology that consisted of a serious mental disability caused by the interruption of the development of intelligence during the intrauterine period or at a very young age (always before the age of 18).
According to its degree of incapacity, the microcephaly/oligophrenia was divided into four types which are more employees due to be considered derogatory and discriminative: idiot (subjects with an IQ lower than 30, unable to communicate with each other and impossible to educate), fool (IQ below 60, unable to read and write), weak (lower IQ at 90, unable to develop mental abstractions) and idiot-savant (self-sufficient to make manual lacking test tasks).
Another leaderboard among individuals with microcephaly/oligophrenia distinguishes the non-recoverable (those who do develop no language), hardly recoverable (those who develop the language, but imperfectly) and recoverable or feeble-minded. All of the feeble-minded can be divided into those who attend school municipality and those attending a special school.
Finally, some authors distinguish the concept of microcephaly/oligophrenia and mental retardation. Thus, they limited the use of the notion of microcephaly/oligophrenia to mental retardation caused by physical or pathological causes (away the delay caused by the lack of stimuli). In this sense, the microcephaly/oligophrenia has an organic cause can be genetic (or prenatal), perinatal (at birth) or postnatal.