SEX DIFFERENCES – PSIHOLOGY 2

In the 1950s a number of doctors treated pregnant women, who were threatening to abort, with drugs called ‘gestagens’ (they are also called progestins). These drugs, which are derived from a synthetic substance resembling testosterone, were given because they were thought to act in a similar way to the natural female sex hormone, progesterone. It was thought, erroneously as it happened, that progesterone and consequently the gestagens would prevent the abortion from occurring. The drug was given by injection, from the 7th or 8th week of pregnancy, often twice weekly for as long as 20 weeks. A number of female children born to these treated mothers were found at birth to have external genitals which resembled those of a boy.

At the same time another group of girls was identified. These children had a genetic defect of their adrenal glands. Because the glands lacked a specific enzyme, the girls were unable to manufacture cortisone in their adrenal glands. Instead, they manufactured the male hormone, testosterone. Testosterone circulated in their body almost from the time they were embryos, and altered the appearance of their external genitals to resemble those of a boy. The girls had a rudimentary penis or, more accurately, an enlarged clitoris, and an apparent scrotum.

Over a period of years, Dr John Money and his colleagues at Johns Hopkins University in Baltimore, U.S.A., have been interested in these two groups of children. After birth, when their correct sex was diagnosed, they required treatment. The girls whose mothers had been given the gestagens in pregnancy usually needed surgery to remove their enlarged clitoris. The girls with the adrenal gland defect needed surgery to remove the big clitoris and cortisone pills to enable them to survive. Both groups of children were reared as girls by their parents, as this was their genetic sex.

When they were between 10 and 14 years old, Dr Money thought that he would try to find out how their behaviour compared with that of matched ‘normal’ girls (matched, that is, for age, socioeconomic background, and I.Q.).

He compared the behaviour of twenty-five affected girls with that of twenty-five normal girls, and found that the affected girls used more energy than normal girls, were judged to be more tomboyish (by adults), preferred what were considered to be boys’ toys – guns and toy cars – rather than those usually thought of as girls’ toys, and had a higher I.Q. Most were indifferent to dolls.

Dr Money’s work suggested that pre-natal testosterone increased a child’s intelligence, her energy, and her tomboyishness. These findings have been criticized on several counts. First, the normal girls he used may not have been good ‘controls’. The mothers who had been given the gestagens, and who had seen their child’s ‘abnormal’ genitals, may have had different expectations of their child, and may have behaved differently to the child. Alternatively, they may have been more anxious about how the child would develop, and may have over-compensated for this anxiety by being more indulgent.

Second, when the intelligence of the affected girl’s parents and that of her brothers or sisters was tested by two of Dr Money’s colleagues, they found that the affected girl was no more intelligent than anyone else in the family.

Three subsequent studies of the children of mothers given gestagens have also failed to find any increased intelligence among them when tested at various ages up to the age of 16.

*12/16/113*

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