Of Chromosomes & Crime

A microscopic piece of genetic material known as the Y chromosome made headlines last week. It is nothing new or rare; every man has one in practically every cell, or he would not be a man. But a few men have two. Richard Speck is said to be one such; his attorneys are now preparing an appeal against his death sentence for the 1966 slaying of eight nurses in Chicago. Another is Daniel Hugon, awaiting trial in Paris on a charge of having murdered a prostitute. His lawyers contend that he is mentally unfit to stand trial because of his chromosomal abnormality, and the Paris court has appointed a panel of experts, including both a psychiatrist and one of the world's most brilliant geneticists, Dr. Jerome Lejeune, to advise it.

The theory that a genetic abnormality may predispose a man to antisocial behavior, including crimes of violence, is deceptively and attractively simple, but will be difficult to prove. The argument in its favor rests upon the fact that in a few prisons sampled in the U.S., Britain and Australia, the proportion of inmates with an extra Y chromosome has been found to be higher than in the general population. The objections to the theory are that no one knows the true incidence of the extra-Y abnormality, and that even when it is shown to exist, no one knows how the second Y can influence personality, let alone criminality.

Supermale? Nature intended every man and woman to have 46 chromo somes per cell: 22 pairs of autosomes, which determine countless characteristics other than sex, and two gonosomes or sex chromosomes. In the female, these are a pair of Xs; in the male, an X and a Y (see diagram). When a sperm fertilizes an ovum, each supplies half the 46 chromosomes for the combination of cells that will grow into a baby. If the sperm contains an X chromosome, the baby gets that X plus one from the mother, and will be an XX girl. If the sperm contains a Y chromosome, the baby gets that plus an X from the mother; the potent male Y overpowers the single X, and it's a boy --normally, XY.

But sometimes, when the first cells are dividing and both lines of chromosomes are supposed to make duplicates of themselves, nature slips up. Instead of splitting them into two neat rows of 23 each, it leaves an extra X or Y in one row. If the supernumerary is an X, the baby has an XXY pattern and will grow into a sterile, asthenic "male," usually with some breast enlargement and mental retardation--a condition that physicians call Klinefelter's syndrome.

This has been recognized since 1959. Despite the factor of low intelligence, it has not been linked with criminality. If the extra chromosome is a Y, the baby gets an XYY pattern and is unquestionably male. Or, as evidence gathered by an all-woman team of researchers in Scotland now suggests, he may be a supermale, overaggressive and potentially criminal. Dr. Patricia A. Jacobs and her colleagues working at Western General Hospital in Edinburgh knew that a number of mentally defective men with a double dose of both sex chromosomes, or XXYY, had been found in Swedish and English institutions as criminals or hard-to-manage inmates.* This made the researchers wonder whether it was the extra Y that predisposed the men to aggression. They decided to check on simpler, XYY cases, previously seldom reported.

Among 197 inmates at Carstairs State Hospital, they found no fewer than seven XYY men, or 3.5% (as well as one XXYY). This, they estimated, was 50 to 60 times the normal incidence. To check this estimate, the Edinburgh investigators examined 266 newborn boys and 209 adult men without finding a single XYY. In a random collection of 1,500 karyotypes, they found only one XYY.

The XYY inmates averaged 6 ft. 1 in. tall, whereas the average for other Carstairs inmates was 5 ft. 7 in. In Mel bourne, Dr. Saul Wiener found that the same was true of four Australians, all XYY, who were doing time for murder, attempted murder or larceny. Dr. Mary A. Telfer of Pennsylvania's Elwyn Institute found five XYY abnormalities among 129 inmates at Pennsylvania prisons and penal hospitals selected for study because of their height.

Property Offenses. The consensus so far among the few investigators who have studied the problem is that an extra Y chromosome seems to be as sociated with below-average intelligence, tall stature and severe acne--traits that might result from the hormone-stimulating effects of the duplicated chromosome. But little more is known about the Y chromosome's effects. Dr. Wil liam Price, who works with the research group in Edinburgh, doubts that the XYY pattern can be linked with crimes of violence or sex. Among the XYY men studied at Carstairs, he points out, the proportion whose offenses were against property--such as petty theft and housebreaking--was greater than that among convicts generally.

The XYY males, according to Price, do not suffer from brain damage, epilepsy, or any recognized psychosis such as schizophrenia. They are psychopaths, also called sociopaths--"unstable and immature, without feeling or remorse, unable to construct adequate personal relationships, showing a tendency to abscond from institutions and committing apparently motiveless crimes, mostly against property."

Scotland's XYY convicts tended to get into trouble earlier (around age 13) than the average (about 18). But among their siblings there was an unusually low incidence of criminality. And in the only case so far reported of an XYY with several children, the abnormality was not transmitted: an Oregon XYY has had six sons, but all have a normal XY pattern.

* Chromosome patterns or "karyotypes" are usually made by taking white blood cells, growing them in the laboratory and dousing them with a weak salt solution. This explodes the cells, separating the chromosomes. These are stained, spread on a slide and photographed. From an enlargement, pairs of chromosomes are laboriously cut out, paper-doll fashion, lined up by size and shape in seven groups, and numbered from one to 22 (the "Denver classification"). X and Y are usually placed at the end.

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