User:JerryFriedman/XYY

In 1965, the geneticist Patricia Jacobs and colleagues published their finding that a disproportionately large number of men in a maximum-security prison—7 out of 197—had the XYY karyotype. This started a theory that "a high percentage of all men who carry X-Y-Y chromosomes have strong criminal tendencies" and even that "the extra Y chromosome seems to cause aggressive or violent behavior". This theory gained great public attention in 1968 after false reports that the infamous multiple murderer Richard Speck was 47,XYY and that his lawyer would argue he thus deserved a lesser punishment. (Speck was actually 46,XY, and his lawyer had no intention of mentioning XYY.) Time ran a story as did Newsweek, and another Newsweek story followed two years later  The results of 47,XYY were called "supermale syndrome", and some linked the supposed criminal predisposition to excessive maleness. Associated legal and ethical issues elicited considerable discussion.

However, others pointed out that the original studies were flawed and the link to violence was "a dangerous myth". The opposition focused particularly on a longitudinal study that screened baby boys in Boston, with the intention of tracking those with XYY throughout their lives. Opponents argued that the study had ethical problems: the parents had not been properly informed of the purpose of the study, and the investigators had to either withhold the karyotypes from the parents or risk that the boys would be stigmatized and possibly become antisocial because of a self-fulfilling prophecy. As no treatment for any symptoms was foreseeable, the study would be of limited value to the subjects. After considerable publicity, the study was canceled. Opponents of the cancelation such as Bernard Davis were "appalled" when, as they saw it, a public-relations campaign stopped scientific research that scientists considered valuable.

Though the idea that an extra Y chromosome caused crime was debunked, it appeared in popular culture. Kenneth Royce wrote a successful novel, The X. Y. Y. Man, whose hero is a burglar struggling with his innate criminal tendencies; Royce wrote seven more books about the character, and Granada Television produced a total of 13 episodes based on the books in the summers of 1976 and 1977. An Italian horror film, The Cat o' Nine Tails, depicted a criminal who killed to keep his XYY karyotype secret. In Robert A. Heinlein's science-fiction novel I Will Fear No Evil, a character says that another character "is mean. An XYY.  Committed his first murder at eleven." From another perspective, a 1971 episode of the British television show Doomwatch, "By the Pricking of My Thumbs...", dealt with prejudice against the XYY syndrome. As late as 1992, the film Alien 3 included a prison planet for violent men called "double Y-chromos".