It is characterized by lack of emotional development, low tolerance of stress and anxiety, inability to accept personal responsibility, and reliance on age-inappropriate defense mechanisms.
"[4] The definition borrowed by the first edition of the DSM (see Diagnosis) was originally published in the Army Service Forces's Medical 203 in 1945 under Immaturity Reactions.
The underlying mechanism of the disorder was originally explained either as fixation (certain character patterns persisting from childhood to adult life), or as a regressive reaction due to severe stress (reversion to an earlier stage of development).
[13] In the 1980s, it was noted that immature personality disorder was one of the most common illnesses invoked by the Roman Catholic Church in order to facilitate annulment of undesired marriages.
[14] In 1978, David Augustine Walton was tried in Barbados for killing two passersby who had offered his mother and girlfriend a ride following an argument, and pleaded diminished capacity resulting from his immature personality disorder; he was nevertheless convicted of murder.
[15] In 1989, a former employee of the Wisconsin Department of Transportation had his claim of discrimination dismissed, after alleging that his employment had been terminated due to his Immature Personality Disorder alongside a sexual fetish in which he placed chocolate bars under the posteriors of women whose driving capabilities he was testing.