I’ve explained what these pieces represent, in the first post of the series. So here is another. In terms of trying to condense a huge topic into a few accessible words, this one was the biggest challenge. But I wanted to get across the point that ‘science’ is not neutral, that biological differences have been read in social terms, and that science is contested.

The history of biology 

While ‘sex’ is commonly used for biology and ‘gender’ for social roles, it’s clear from history that things are more complicated. 

Blood has long been seen as a key bodily fluid. In medieval and early modern medicine, it was one of the ‘four humours’, which could cause disease if there was an excess; the amount in the body could be controlled by diet and regulated by bloodletting. Menstrual blood was considered to be the result of women having more spongy flesh which took up more fluid from their diet, and many disorders in women were attributed to menstrual blood accumulating in the wrong place. By the nineteenth century, those arguing against women’s education suggested that too much use of the mind would deprive the womb of the blood needed to make a baby. Ideas about gender roles clearly influenced how biology was seen.

In the early twentieth century, when blood chemistry was still developing as an area of medicine, differences between men’s and women’s blood were noted. On average, women had lower levels of haemoglobin and of calcium. These biological differences were quickly interpreted in social terms. Women’s lower haemoglobin meant they should not exert themselves too much: their lower calcium made them more ‘highly strung’ and less ‘stable’. In England, those interpretations were then used by a 1923 Board of Education report into whether boys and girls should have the same school curriculum. The report was evidence of concern about the risk of ‘physical fatigue and nervous overstrain’ in girls, and it was recommended that they should be set less homework because it was assumed that they would also be doing domestic duties at home. The report drew on the second edition of Dr William Blair Bell’s book The Sex Complex, published in 1921, on the effects of puberty on both sexes, although the authors noted that this was ‘not yet generally accepted by physiologists’.