Women鈥檚 scores on spatial reasoning tests vary according to the stage of their menstrual cycle, says a German team.
The scores are lower during the early stage of the cycle, when oestrogen levels are higher, and they peak during menstruation, when testosterone levels increase.
鈥淪cores on mental rotation tasks are very strongly influenced by sex hormones and by the sex of the participant,鈥� says Markus Hausmann of the Ruhr-Univerist盲t in Bochum.
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How testosterone exerts its effect is not clear, says Hausmann. But the findings fit in with other research on sex hormones and spatial reasoning, says Daryl O鈥機onnor at Leeds University. 鈥淭his is interesting work, but it isn鈥檛 a surprise,鈥� he says.
Mental gymnastics
Hausmann鈥檚 team collected blood samples every three days over six weeks from 12 women in their twenties and thirties. They measured blood concentrations of oestradiol, progesterone, testosterone, luteinizing hormone and follicle-stimulating hormone.
The women were given three tests of spatial reasoning at the same time as the blood samples were taken. The mental rotation task was the most complex, requiring the women to match three-dimensional shapes presented in different orientations. This task was the only one to produce significant differences in performance in relation to oestrodiol and testosterone levels.
Last year, O鈥機onnor investigated the effects of boosting testosterone in men. At higher than normal physiological levels, testosterone increased men鈥檚 verbal dexterity. O鈥機onnor thinks the excess testosterone is converted to oestradiol, and speculates this might provide the boost to verbal reasoning while also inhibiting spatial reasoning.
鈥淚f this is right, it could also help explain Hausmann鈥檚 results,鈥� he says.
But O鈥機onnor thinks varying levels of testosterone and oestrogen are unlikely to significantly affect intelligence. 鈥淭hese differences are really academic 鈥� they鈥檙e slight. But we need to tease out the effect of the hormones on reasoning,鈥� he told New 杏吧原创.
More at: Behavioural Neuroscience (vol 114, p1245)
