Fetal levels of testosterone affect how children’s brains respond to facial expressions

It seems that everything that comes out of Simon Baron-Cohen’s lab is more interesting than the last. This study, hot off the e-press, shows that levels of testosterone in the fetus can predict how certain parts of the brain respond to faces years later. 

These guys measured testosterone in amniotic fluid around 13-20 weeks gestation and then had the Herculean task of following up 25 of the boys aged 8-11 years (as a fellow longitudinal researcher, I can tell you that their RAs probably put in some long hours to do this!). The boys at this age that had higher levels of testosterone when they were fetuses showed more response in the reward system of the brain when viewing happy faces compared to fearful faces. The authors suggested that early levels of testosterone might help some parts of the brain develop with a bias towards pleasant, or happy, information. I think it’s amazing that work is being done to show how prenatal factors can influence people’s neurological and emotional processes so much later in life.



The study is available publicly through Open Access here. Anyone interested in some of Baron-Cohen’s other work on fetal testosterone, autism, and his theory of the “extreme male brain” should check out his website.

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2 thoughts on “Fetal levels of testosterone affect how children’s brains respond to facial expressions

  1. @James Hill: That is the implication, although it is difficult for this study to answer direct questions about sex differences because they only looked at males. So the only thing this study can say is, for males, more testosterone in the womb = more bias towards happy faces compared to fear faces in childhood.The Wibral, et al (2012) study you've linked to there is an interesting one, although it suffers from the same bias in that they only studied males. Additionally, Wibral and colleagues looked at immediate behavioural reactivity to testosterone injection in adults. Baron-Cohen's study, in my opinion, is superior in terms of answering questions about the effect of hormones on the developing brain. In other words, Baron-Cohen and colleagues were able to suggest that testosterone has effects on behaviour mediated by changes in brain development (although a longitudinal study would have been even better suited to address this issue). To me, this makes more sense than an immediate effect of testosterone on a complex behaviour such as lying. However, we shouldn't discredit the effect of rapid increases of hormones on behaviour completely – for example, some studies suggest the rapid increase in oestradiol can lead to depressive symptoms in female adolescents – which may be why the onset of puberty is such a volatile time for the onset of mood disorders.In other words, hormonal effects on the prenatal brain, and rapid, immediate (but temporary) increases in peripheral hormone levels in adults are two different things but both worthy of investigating.I hope that makes sense.

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