Behaviour disorders and pattern of crime among XYY males identified at a maximum security hospital.

Two New Cases of XYY Chromosome Complement: And a Review of the Literature

“…Both young men were over 6 feet tall (7,30), impulsive, aggressive and antisocial, to a degree that they resemble the criminal populations studied by Falek (1 I), Nielsen (23,26) Telfer (38) and Wiener (43). This abnormal behaviour began in both patients at a very early age and they therefore resemble the delinquent populations studied by Borgaonkar (4), Cowie (8) and Marinello (21).…”

“…The XYY men reported are often impulsive, aggressive and antisocial and have criminal records beginning at an earlier age than other delinquents or criminals (30). Even six of the nine cases of XYY chromosome complement found in general population surveys (39,44) showed a proclivity to impulsive destructive and antisocial behaviour.…”

“…On the one hand, approximately 1:500-1:900 live male newborns have this complement (3,9,24,39) but very few seem to come to clinical attention; on the other hand, surveys of institutions for the retarded (6,18), the mentally ill (2,12,16,22), the criminally insane (5,9,18,28,30) and the aggressive offender (11,21,23,26,38) have all shown a higher incidence of the XYY complement than would be expected in the general population. Some investigators (4,15) have tried to explain these individuals, in mental institutions and prisons, on the basis of their being tall and therefore more likely to be considered as dangerous by judges and psychiatrists.…”

“…Some investigators (4,15) have tried to explain these individuals, in mental institutions and prisons, on the basis of their being tall and therefore more likely to be considered as dangerous by judges and psychiatrists. Other authors have described them as having more immaturity, emotional lability, and criminality than the normal population (44), and even more emotional instability and impulsivity than other inmates (30). Clinical case histories in the literature generally focus on the unusual and pathological, and one cannot overlook the need for genetic population studies to assess to what extent various sex chromatin abnormalities occur without manifest psychopathology.…”

“…All seven were significantly taller than average but had no other physical abnormalities, and none were psychotic. Price and Whatmore (30) added two more cases from the 119 "mentally diseased" dangerous patients from the same hospital (1.9%) for a total of nine XYY patients among 340 criminal, mentally retarded or diseased patients. All of these cases were unusually tall and in fact 30 percent of the men who were 6 feet tall, or more, had double Y chromosomes.…”