[5][6][7][8] Neuroscientist Gina Rippon defines neurosexism as follows: "'Neurosexism' is the practice of claiming that there are fixed differences between female and male brains, which can explain women's inferiority or unsuitability for certain roles.
"[5] Fine and Rippon, along with Daphna Joel, state that "the point of critical enquiry is not to deny differences between the sexes, but to ensure a full understanding of the findings and meaning of any particular report.
[citation needed] The history of science contains many examples of scientists and philosophers drawing conclusions about the mental inferiority of women, or their lack of aptitude for certain tasks, on the basis of alleged anatomical differences between male and female brains.
[2] In the late 19th century, George J. Romanes used the difference in average brain weight between men and women to explain the "marked inferiority of intellectual power" of the latter.
Although overtly sexist statements may no longer have a place within the scientific community, Cordelia Fine, Gina Rippon and Daphna Joel contend that similar patterns of reasoning still exist.
"[15] Charges of neurosexism may then be moved against the PHT if these alleged hormonal differences are interpreted as causing the male/female brain distinction and in turn are used to reinforce stereotypical behaviours and gender roles.
[15] The notion that there are hard-wired differences between male and female brains is particularly explicit in Simon Baron-Cohen's empathising-systematising (E-S) theory.
In a 1999 study, Gur et al. found a link between the amount of white matter in a person's brain and their performance on spatial tasks.
[23] Fine argues that results like these should be treated with caution, because, given the sample size and the number of relationships tested, the correlation found between white matter volume and performance in the tasks could be a false positive.
[27][19] A notable dispute in 2010 between Fine and neuroscientist Simon Baron-Cohen in The Psychologist magazine centred on a study into sex differences in the responses of newborn babies to human faces and mechanical mobiles.
Jordan-Young conducts a comprehensive review of these studies, finding them to neglect four broad categories of variables that plausibly affect psychosexual development: "(1) physiological effects of CAH, including complex disruption of steroid hormones from early development onwards; (2) intensive medical intervention and surveillance, which many women with CAH describe as traumatic; (3) direct effects of genital morphology on sexuality; and (4) expectations of masculinisation that likely affect both the development and evaluation of gender and sexuality in CAH.
Neglecting these four categories in our methodology of studies into those with CAH then favours the sex difference hypothesis, providing a clear example of neurosexism in scientific research.
[35] The study used diffusion tensor imaging to investigate white matter connections in the brains of 949 participants ranging from 8 to 22 years old.
Cliodhna O'Connor and Helene Joffe examine how traditional media, blogs, and their comment sections autonomously project prevailing understanding of sex differences (emotion-rationality dualism and traditional role divisions) onto mute findings, construing men as purely rational and women as highly emotional, noting how both social representation theory and system justification theory may be causing bias in the interpretation of these findings.
[37] According to Cordelia Fine and Gina Rippon, there are systematic methodological issues in the neuroscience of sex differences that increase the chances of neurosexism.
In Fine's view, neuroscientists tend to take a snap-shot comparison (looking at current neural differences) and describe the results as "hard-wired", without considering that the observed patterns could change over time.
However, given the aforementioned concept of brain plasticity, the notion that these connectivity differences are exclusively a result of natural biology can be challenged.
[citation needed] This is because plasticity introduces the alternative possibility that individuals' sex-specific learned behaviours could have also impacted their brain connectome.
[citation needed] Fine[38] has criticised the small sample sizes that are typical of Functional Neuroimaging (FNI) studies reporting sex differences in the brain.
She takes a sample of thirty-nine studies from Medline, Web of Science, and PsycINFO databases, published between 2009 and 2010, in which sex differences were referred to in the article title.
Not only do false positives misinform, but they also "tend to persist because failures to replicate are inconclusive and unappealing both to attempt by researchers and to publish by journals".
In a review of Delusions of Gender, he said that "Ultimately, for me, the biggest weakness of Fine's neurosexism allegation is the mistaken blurring of science with politics", saying that "You can be a scientist interested in the nature of sex differences while being a clear supporter of equal opportunities and a firm opponent of all forms of discrimination in society.