The term "arrested development" has had multiple meanings for over 200 years. In the field of medicine, the term "arrested development" was used, in 1835-1836, to mean a stoppage of physical development; the term continues to be used to indicate a stoppage of physical development.
However, in the UK Mental Health Act of 1983, the term "arrested development" was considered a form of mental disorder consisting of severe mental impairment, as a lack of intelligence.[1] Other researchers have objected to the notion that mental development can be "arrested" or stopped, preferring to consider the mental status as developing in other ways, rather than the notion of mental growth as arrested. Consequently, in psychological terminology, the term "arrested development" is no longer used by them in referring to a developmental disorder in mental health.
In the field of developmental biology, the related term "neoteny" (or juvenilization) means the retention, by adults in a species, of traits previously seen only in juveniles.