The Mental Health Act 1983 defines psychopathic disorder as a persistent disorder or disability of mind (whether or not including significant impairment of intelligence) which results in abnormally aggressive or seriously irresponsible conduct. The cardinal features are: absence of normal feelings for other people such as love, affection, sympathy and condolence; a tendency to antisocial impulsive acts with no forethought of the consequences; failure to learn by experience and to be deterred from crime by punishment; and absence of any other form of mental disorder that would explain the unusual behaviour. The corresponding American terminology is ‘anti-social personality disorder’. (See MENTAL ILLNESS.)