Sex and Neuroscience, a new series


The coming week I will post articles about gender and/or sex and neuroscience. Topics with sex or gender and brains will be chocolate, computer game play, depression, medical education and brain sex differences, so stay tuned.

Now what is the difference between gender and sex?
Sex = male and female

Gender = masculine and feminine

So in essence:

Sex refers to biological differences; chromosomes, hormonal profiles, internal and external sex organs.

Gender describes the characteristics that a society or culture delineates as masculine or feminine.

So while your sex as male or female is a biological fact that is the same in any culture, what that sex means in terms of your gender role as a ‘man’ or a ‘woman’ in society can be quite different cross culturally. These ‘gender roles’ have an impact on the health of the individual.

Some common misconceptions about sex and the brain, since that will be the main focus of this series:

  • The first misconception is that sex influences are small and unreliable. They are not. No evidence suggests that the average effect size in the domain of sex influences on brain function differs from the average effect size found in other domains of neuroscience.
  • Another misconception holds that average differences between the sexes result from a few extreme cases in a distribution. This is not the case.
  • The differences within a sex are much more substantial than those between the sexes, the implication being that sex influences can therefore be dismissed as trivial. Which it is not.
  • The fourth misconception is that all sex differences, once established, can be completely
    explained by the action of sex hormones, typically oestrogen. The unstated assumption underlying this view is that male and female brains are identical except for fluctuating (and unnecessarily complicating) sex hormone influences. The effects of circulating sex hormones cannot fully account for all sex differences observed in the adult brain, as many sex differences persist even in the absence of these hormones.
  • A final misconception holds that if no sex difference exists in a particular behaviour, it can be assumed that the neural substrates underlying that behaviour are identical for both sexes. However, numerous studies report sex differences in neural activity despite no behavioural difference between the sexes.
Larry Cahill (2006). Why sex matters for neuroscience Nature Reviews Neuroscience, 7 (6), 477-484 DOI: 10.1038/nrn1909