Friday, November 19, 2010

“His chromosomes made him do it” — again

Posted by Nathaniel Comfort on 11/19 at 09:22 PM

Ohio governor Ted Strickland recently commuted the death sentence of Sidney Cornwell, a Youngstown gang member who has been on death row since 1997. He was convicted of killing a three-year-old girl when he and other gang members opened fire on the apartment of a rival gang member. Cornwell confessed to aggravated murder in the case. So why was his sentence commuted?

Because, said a judge, his chromosomes made him do it.

Sidney Cornwell is an XXY male, a condition known as Klinefelter syndrome. Cornwell’s sentence was commuted because one of three Circuit Court judges hearing his appeal decided that his karyotype—the pattern of his chromosomes—reduced his responsibility below the threshold of Ohio’s severest penalty.

Klinefelter syndrome was first associated with the presence of an extra X (a so-called sex-chromosome aneuploidy) in 1959. In 1962, the English researcher William Court Brown noted the increased frequency of sex-chromosome aneuploidies in a local mental institution, compared with the general population. Many of the inmates of the hospital had committed crimes. Court Brown wrote that he thought it “likely” that “an abnormal sex-chromosome complement may predispose an individual, perhaps in a suitable environment, towards delinquency.”

In 1965, Court Brown’s colleague Patricia Jacobs, published a more detailed study, noting that “It is well known that one per cent of males in institutions for the mentally sub-normal are chromatin-positive [have a second X chromosome] and that the majority of these have an XXY sex chromosome constitution’.”

But it was the XYY males that drew their attention. “At present it is not clear,” they wrote, “whether the increased frequency of XYY males found in this institution is related to their aggressive behaviour or to their mental deficiency or to a combination of these factors.” The next year, an American researcher, Mary Telfer, published similar results suggesting a link among mental deficiency, violent crime, the XYY genotype, and certain physiognomic and physiological traits, including acne.

It was too good not to be true.

True enough, the vast majority of violent crime is committed by people with a Y chromosome. If one Y was bad, two must be disastrous. In the sixties, when medical genetics was just coming into its own as an acknowledged subspecialty of medicine, such a clear-cut association was irresistible. It seemed obvious that the extra Y chromosome turned normal males into hyper-aggressive, hypersexual monsters. The Y became the crime chromosome.

XYY males featured in several celebrated criminal cases. In 1966, Richard Speck systematically raped, tortured, and murdered eight student nurses from a Chicago hospital. The only problem was, Speck was a normal XY male. But that didn’t stop his lawyers from attempting to get him off on an aneuploidy defense.

However sensational and appealing the idea, the scientific community understood that the existing data were inconclusive. In 1968, two Harvard researchers, Stanley Walzer, a psychologist, and Park S. Gerald, a respected human cytogeneticist, teamed up on a federally funded, long-term study sex chromosome aneuploidy and behavior. They looked at XXYs, XYYs, XXXs, XOs—any sex chromosome anomaly. The study went on peacefully until 1974, when Jonathan Beckwith, a hotshot bacterial geneticist with a strong social conscience, got wind of it. Beckwith had been doing some reading in the history of eugenics. He was appalled by the parallels between the XYY male hypothesis and the genetic determinism of the early twentieth century. To Beckwith and King, the study seemed an extension of older studies that sought to partition society along biological lines. Walzer and Gerald’s study became, in Beckwith’s mind, “the XYY study,” a scientific rationalization of genetic determinism.

Beckwith recruited his friend and colleague Jon King from MIT to try to put a stop to the Walzer & Gerald study. They were members of the Cambridge activist group Science for the People, which had recently protested recombinant DNA research in Cambridge. Beckwith and King led the charge against the Walzer and Gerald study, putting on so much pressure that Walzer and Gerald ultimately stopped the research component (they continued to follow the patients already in the study).

Beckwith and King were concerned about the biomedical establishment stereotyping individuals—especially children—as crime-prone based on their karyotype. They feared a self-fulfilling prophecy, in which someone might think they were fated to a life of crime and therefore lead one. While Cornwell’s case is one of medicalization and decriminalization, it is still an example of genetic fatalism. He can’t help himself. His chromosomes made him do it.

Behavioral tests of competency are legitimate tools in the determination of culpability. They ask: Can we hold the man responsible for his actions—based on his actions? But a blanket cytological get-out-of-lethal-injection-free card betrays the same simplistic genetic determinism of forty years ago. The issue today is the medicalization, rather than criminalization, of violence, but the essential issue is the same: to what extent does “innate” mean “not responsible for”?

Check it:

Beckwith, J. R. and J. King (1974). “The XYY syndrome: a dangerous myth.” New Scientist 64(923): 474-476.

Court Brown, W. M. “Sex Chromosomes and the Law.” The Lancet 280, no. 7254 (1962): 508-09.

Denno, D. W. (1996). “Legal implications of genetics and crime research.” Ciba Found Symp 194: 248-256.

Jacobs, P. A., M. Brunton, et al. (1965). “Aggressive behavior, mental subnormality and the XYY male.” Nature 208: 1351-1352.

Steinfels, M. O. and C. Levine (1980). “The XYY controversy: researching violence and genetics.” Hastings Cent Rep 10(4): Suppl 1-32.

Telfer, M. A., D. Baker, et al. (1968). “Incidence of gross chromosomal errors among tall criminal American males.” Science 159(820): 1249-1250.

Walzer, S., G. Breau, et al. (1969). “A chromosome survey of 2,400 normal newborn infants.” J Pediatr 74(3): 438-448.

Tags: xyy xxy genetics aneuploidy chromosomes aggression genetic_determinism richard_speck sidney_cornwell