Extra Y Extra Violent
Men with an extra Y chromosome is a pretty common genetic disorder (1 out of 1,000 biologically male humans) that, at its worst, has only two symptoms: above-average height and an increased susceptibility to learning disorders.
In fiction, however, being XYY makes you a criminal! It's simple logic:
This trope is based on a couple of widely-reported studies from the 1960s which didn't pan out on further research (see the Real Life
section). Media, however, didn't get the memo.
This trope is likely to show up in crime dramas and other works that involve both bad guys and genetics researchers or genetic typing. It's usually either the reason the bad guy is bad or an aggravating factor in his badness.
- Deadfall, from Artemis: Requiem, was artificially given an extra Y chromosome. His powers include super strength and the ability to manipulate testosterone. He is described as perhaps the most aggressive male on earth.
- Alienł. All the prisoners at the penal colony are XYY males. Interestingly, the prison was actually shut down and these were the prisoners who elected to stay. Many of them claim to be trying to change as well.
- Referenced in Scary Movie 3.
- The biology research institute in The Cat o' Nine Tails is researching it while the murders happen around it.
- The XYY Man began life as a series of novels by Kenneth Royce, featuring the character of William (or Willie) 'Spider' Scott, a one-time cat-burglar who leaves prison aiming to go straight but finds his talents still to be very much in demand by both the criminal underworld and the British secret service. Scott has an extra "y" chromosome that supposedly gives him a criminal predisposition - although he tries to go straight, he is genetically incapable of doing so.
- Played utterly straight in the Star Trek short story "The Procrustean Petard": the Enterprise crew is gender-flipped by an alien device which doesn't know how to deal with Half-Human Hybrid Mr. Spock, so it makes him XYY instead.
- This trope is mentioned in Nightlines, a novel by John Lutz.
- Mentioned in Succulent Prey, by Wrath James White, in which a character states that the link between an extra Y chromosome and serial killers has been shown to be false.
- In Full Cry, by Rita Mae Brown, two characters discuss criminals, with one claiming many criminals were “born bad,” giving as an example that most men who are born XYY can’t control their violent behaviour.
- In Gone for Good, by Harlan Coben, Will wonders at one point whether Ghost, who is very aggressive and displays psychopathic tendencies, has an extra Y chromosome.
- In Missing Pieces, a novel by Joy Fielding, a character is asked what causes someone to become a violent sociopath. He responds that there is no consensus as to whether it is more nature or nurture and cautions that attributing such behaviour to an extra Y chromosome is problematic.
- The short poem, "It's Easy As XYY", refers to this trope, linking an extra Y chromosome to violence.
- In "Sam, Soren and Ed," a short story by Guy Vanderhaeghe, Ed describes another character, whom he first sees aggressively practising martial arts, as an “extra-Y-chromosome type.” After a confrontation with his estranged wife, Ed almost has to fight the man, but the police show up and diffuse the situation.
- In Slow Motion Riot, by Peter Blauner, Andrea refers to a character who seems to "love to do crimes" as acting like someone with an extra Y chromosome.
- This trope plays an important role in The Campus Detective: The Sociopath, by Dave Larson.
- The Stranger in Goldrush, by Sheila Bush, mentions this trope. A character briefly refers to "macho psychopaths" with extra Y chromosomes.
- The connection between criminal violence and an extra Y chromosome is touched upon by a character in Child of My Right Hand, by Eric K. Goodman, as he thinks about genetic predispositions.
- In Hybrids, by Robert J. Sawyer, the link between an extra Y chromosome and a predisposition to violent behaviour is mentioned. A character even suspects another character of being XYY based on his physical appearance and personality.
- In Seduction, by Catherine Gildiner, a character believes there are many XYY men in prison, whom she describes as violent and possessing low intelligence.
- In The Vision, by Dean Koontz, Mary wonders whether it is possible for some people to be "born evil" and recalls having read about men with an extra Y chromosome, who are described as the "genetically ordained criminal type."
- At one point in Other Men’s Daughters, by Richard Stern, several social issues and controversies are mentioned, including the "social peril of the XYY male with the criminal valence in his cells."
- In Transfiguration, by Paul Weber, a doctor mentions this trope while discussing Apollonia's strange chromosomal abnormalities. The doctor states that people used to think XYY males had a higher rate of criminality but admits this has been shown to be false.
- This trope plays a role in Gone to Earth, by Rick Boyer. Interestingly, the novel discusses not only the idea that XYY men have a propensity for crime and aggression but also mentions other features including having acne, prominent facial hair, lower intelligence and psychological issues as well as being taller and stronger.
- In The Labyrinth Key, by Howard V. Hendrix, a character explains that society has always searched for a biological way of detecting future deviant behavior, and includes the XYY studies as an example.
- In Midnight Admirals, by Douglas Muir, two characters discuss a killer and one explains the criminal can’t be XYY because he doesn’t display low intelligence.
- In Good News, Bad News, by David Wolstencroft, a character refers to Latham as “XYY” and ponders how men were the cause of most wars and are blamed for almost all the violence in the world.
- In Soul, by Tobsha Learner, a character searches for an explanation as to why some men are predisposed to violence and murder. She considers that an extra Y chromosome may be involved, but this explanation doesn't pan out.
- In Vickers, by Mick Farren, a big muscular character who seems to like violence is referred to as "an Australian surfer with an extra Y chromosome."
- Interestingly, in Middlesex, by Jeffrey Eugenides, XYY boys are referred to as "dreamers and loners," rather than the common stereotype.
- The Season 5 finale episode "Born to Kill" of CSI: Miami referenced this trope. A couple knew that their son had this condition and constantly treated him with suspicion because of it. When their daughter accidentally kills their other daughter by pushing her down the stairs, she claimed he did it on purpose; this is what actually turned him violent.
- Played with in Criminal Minds, where a killer claims that he's XYY, and that's why he kills. However, Rossi replies that the study linking that condition to criminal behaviour was debunked years ago.
- An episode of Forever Knight centers on a legend that a (female) vampire who mated with an XYY male "higher than high, under the light of the full moon" would become human. The XYY human did have extra violent tendencies.
- The XYY Man, the first of Kenneth Royce's novels, was transferred to British television by Granada TV, in a three-part adaptation with Stephen Yardley playing Scott. The adventures of Scott caught the public imagination and ten more episodes followed in 1977.
- In one episode of Doomwatch, “By the Pricking of My Thumbs…”, a teenager faces discrimination because he is XYY. The episode features a scientist who is convinced that having the extra Y chromosome predisposes a person to criminal behavior, but this position is meant to be seen as misguided.
- In "Born Bad", an episode of Law & Order, a lawyer argues that his client should not be found guilty since his extra Y chromosome predisposes him to be violent. It went horribly right, the client bought the arguement so much that he begged to be jailed for life. He was a teen.
- In a 1993 episode of the Talk Show, The Phil Donahue Show, a psychiatrist discusses a patient he believes committed murder due to having an extra Y chromosome.
- In a Nick Downes cartoon, a tough cowboy is known for "his fast gun, mean temper, and extra Y chromosome."
- Serial killer Richard Speck was widely (and incorrectly) reported to be XYY, which popularized this trope.
- The source of this idea was some medical studies from the 1960s, which claimed that the XYY genotype actually could cause a propensity for violent behaviour. The studies found that male prison inmates who were unusually tall had a slightly higher incidence of XYY than among the general population. Which was either a coincidence, or a false correlation that didn't properly account for a) how XYY men (like people with other chromosomal abnormalities) have an increased risk of learning disabilities that might hinder their ability to get away with a crime and b) selecting for height in itself increases the chance of finding XYY carriers. Though this idea has been discredited, it still pops up now and then.
- Generally speaking, prison populations have considerable concentrations of people with significantly low IQ, for whatever reason.