The Spiritual Anthropologist

Where Alcohol and Anthropology Meet

A Reply to Gina Rippon’s Commentary on Sex Based Differences in The Brain

By alcanthro Leave a Comment Sep 1 1

In Men and Women’s Brains Aren’t Really That Different, Gina Rippon provides an excerpt from her book on gender differences in the brain. Unfortunately, the piece reads more like an op-ed than a form of sci-com. It could be that in other areas of the book, there is substance which justifies her position, but there is absolutely nothing in the article which does so. There are also two issues that I have with the claim. The first issue is a semantic one. Scientists need to become better at differentiating sex and gender. The second issue is in actual substantiation and a contradiction between the science that does exist and her position.

The Semantic Issue

From a semantic perspective, it seems that Gina is referring to potential sex based differences in the brain, rather than gender based differences. I’ve written extensively on the concept of gender, both here on Medium and elsewhere. Gender is what I refer to as an eidos: a culturally defined role which is related to, but distinct from, underlying biological features. 

Sex is biological. Gender is cultural. While the two are related, they are not the same, and while I admit that I do sometimes use gender terms and sex terms in place of one another, I do try to make sure that I avoid this error, as all science communicators should. Indeed, science communicators are apt to point out the distinction between sex and gender, when there is pseudo-scientific or anti-scientific rhetoric used to attack transgender people and other groups, but we often fail to recognize the distinction between sex and gender, in our own work, thus clouding the issue and spreading the misunderstanding further.

The Science

The second issue is that science does not seem to justify her position. While it may be true that the science on sex based differences is not as robust as some might think, that’s not enough to argue that there is no inherent sex based difference in how the brain functions. There are a number of reasons to think that the brains of females would be, on average, different from the brains of males. These differences could take multiple forms. Gross size of regions of the brain are of little interest. On that matter, I agree with Gina. Functional differences are what matters. These differences can be permanent or transient. 

Impact of Hormones on Functional Connectivity

The greatest reason to think that such differences between sexes exists is that males and females have different levels and cycles of hormones, and hormones seem to impact brain function. For instance, according to Lu et al. 2019, changes in sex hormones during perimenopause apparently changes functional connectivity in the brain. Additionally, Hahn et al. 2016 noted that high doses of testosterone caused significant functional changes in adult brains in female-to-male transsexuals. This finding is inconsistent with the idea that sex dimorphisms are due to differences in enculturation and how the brain adapts to expectations. The adult brain of a male-to-female transsexual is unlikely to undergo such rapid and precise changes in expectation simply because they are starting transition. Given that hormones have such a large impact on functional connectivity, and there are significant differences in hormone levels between males and females, it becomes very difficult to argue that such differences are almost entirely due to conditioning.

For Gina’s position to be robust, she would have to respond to these issues. Either she would have to provide justification for the claim that hormones do not impact brain connectivity, or that somehow, even with this theory in place, it is conditioning, and not hormonal differences, that override and result in the dimorphism in brain function, and that without this conditioning, somehow the difference in hormones between males and females does not result in dimorphism. 

Fetal Research

But to further investigate the matter, it is important to conduct research on neurological distinctions that arise during fetal development. If sex based differences are due to later enculturation, they should be less likely to arise during fetal development. One such study is Sex differences in functional connectivity during fetal brain development, conducted by Wheelock et al. 2019. Gina actually provides criticism of this paper, and while there are some valid concerns, most of the criticism is not exactly valid. Of interest are the sample differences between the male and female participants, the testing of a large number of potential regions of interest, and the use of non-parametric tests due to a lack of apparent normality.

The sample sizes were unequal between male and female participants, and ages varied considerably, and during that time, cortical development varies considerably. If the age distribution of females was significantly different from the age distribution of males, in the study, the age difference could account for apparent sex based differences. However, the researchers specifically checked to see if there was a difference in gestational age at the time of the scan. The results of the test can be found in Table 1 — Demographic Information, and the results do not indicate a difference between the two populations.

Additionally, Gina mentioned that there are a lot of potential regions of interest. And on this matter, I agree. If a researcher performs enough hypothesis tests, there will be some that are successful. It’s a simple matter of chance. Therefore a followup study needs to be conducted to further justify that these regions of interest are not simply false positives, but actual differences in development.

Gina also commented on the use of parametric tests and their low statistical power. However, this argument really makes no sense. A hypothesis test is a statistical form of proof by contradiction. The null hypothesis is simply an initial assumption that is made, with the intent to try to find a result that contradicts it. The simpler the hypothesis — and non-parametric tests make fewer assumptions than parametric tests — the less likely the hypothesis is to be falsified.

In essence, this idea is the flip side to Occam’s razor: if a “simpler” explanation is more likely to be true, all else being equal, then it is less likely to be falsified. Therefore, it is more difficult to reject the null hypothesis. In the case of this study, the null hypothesis is equality, and so when using a non-parametric test, as is required because there wasn’t sufficient justification to assume normality, it would be more difficult for the researchers to conclude that the regions of interest are unequal.

Additionally, Gina mentioned that non-parametric tests cannot test for multivariate influences. While it is true that tests like the Spearman rank correlation is univariate, there are multivariate non-parametric tests available. Since Gina is concerned about the lack of attention to other variables, perhaps the solution is to see if the raw data is available and perform such a multivariate non-parametric test.

While there are some issues with a key study which indicates that sex based differences in the brain start to emerge in-utero, this kind of study does not exist in a vacuum. Alone, the study does not provide much justification. But given that we see various sex based differences, in fetal development, and in childhood, and in adolescence, across various cultures, the compass needle is pushed far away from the theory that the sexes are neurologically the same. It’s true that it would be more powerful, if it were repeated. If the same regions of interest were tested and similar results were found, then it would be justification that these hits were not just due to random chance.

Yes; more research should be done, as is generally the case in science. And perhaps it is reasonable to dismiss the claim that there are sex based differences in the brain. However, when it comes to claims that there is no difference, the claim is simply unjustified. Moreover, the compass needle does point away from that theory, especially when coupling the findings of fetal studies with studies that indicate that hormones have a significant impact on functional connectivity in the brain.

Plants vs Animals

By alcanthro Leave a Comment May 15 0

Vegans have an interesting view of the plant-animal divide. I don’t like it.

Continue

Skeptical Tawny Frogmouth

By alcanthro Leave a Comment May 7 2

So, I found an interesting photo of a tawny frogmouth. Found in Australia, it’s a bird that looks a lot like an owl, but it’s not one. It’s just an example of parallel evolution. It looked perfect for a skeptical meme, but I felt like it was important to include the attribution, especially since it […]

Continue

Online Communities and Massive Multiplayer Online Games as Homes

By alcanthro Leave a Comment May 1 0

Most people think of homes as physical places. But a home can be a lot more than that. A home is every bit as much a product of who as it is where and what. Here are three definitions of “home” provided by Merriam-Webster: one’s place of residence the social unit formed by a family […]

Continue

Revising Public Health Practice

By alcanthro Leave a Comment Apr 24 0

Vaccine Banner

Sanitation, vaccines, control of various environmental factors that affect health, and much more have greatly improved our quality of life and our average lifespan. But while public health practice has come a long way, there are still numerous areas of improvement. Not only must public health practice improve in terms of communication with the public, […]

Continue

The Absurd Opposition to Circumcision

By alcanthro Leave a Comment Mar 29 1

Vaccine Banner

Both the CDC and the WHO have produced recommendations for circumcision. While there isn’t enough information to create a full plan of action, recommending universal circumcision, the science is fairly solid when it comes to counting the claims of anti-circs. I use that term because in many cases, the kind of science denial seen among […]

Continue

The Miseuse of the word Myth

By alcanthro Leave a Comment Feb 20 0

I wasn’t going to write this article, but I suppose it fits this month’s theme on Medium: reasonable doubt. In common parlance, “myth” is used to mean something that is false or something that people believe without justification, like an urban legend. But for a mythicist and anthropologist, like myself, that’s simply not the case. […]

Continue

The Pseudoscience and Science of Astrology

By alcanthro Leave a Comment Feb 18 0

There might be something to astrology after all, but not in a mystical sense. I’ve been thinking about writing this article for a while, but I just wasn’t sure if anyone would be interested. Some people might even take it as a defense of astrology. I’m still not sure, but after reading Martin Rezny’s review of […]

Continue

From Preprints to Omniprints

By alcanthro Leave a Comment Feb 17 0

Starting with ArXiv, the idea of preprints has been increasingly in popularity for some time. But now is the time for omniprints. Preprints were a good start. And Crossref has been indexing more and more preprints, with preprints outpacing journal articles by far (Crossref). There are a number of servers, including ArXiv and its derivatives, […]

Continue

Ramblings on a Paraconsistent Reality

By alcanthro Leave a Comment Feb 17 0

There are two camps of science: the provisional verification camp, which was really the first to arise, in a formal sense, when Francis Bacon formulated “the scientific method.” The second camp arose when philosophers such as Kant and Hume realized that there was an issue with induction. They questioned why repeated observations, consistent with a […]

Continue
  • 1
  • 2
  • 3
  • …
  • 6
  • Next Page »

Tags

afterlife anthropology atheism bigotry bioarchaeology business calvados cocktail cognitive model culture definitions eidos epidemiology epistemology evolution facebook fMRI gender gods harris history long pepper medicine mental health old fashioned penguinism pertussis psychology public health race religion religiophobia religious rejectionist research satanism science sex simple syrup Smart sociology soda Sq'wak thermodynamics twitter vaccines

Recent Posts

  • A Reply to Gina Rippon’s Commentary on Sex Based Differences in The Brain
  • Plants vs Animals
  • Skeptical Tawny Frogmouth
  • Online Communities and Massive Multiplayer Online Games as Homes
  • Revising Public Health Practice

Categories

  • Alcohol
  • Cocktails and Ingredients
  • Comics
  • Health & Medicine
  • Historiography
  • Humor
  • New Research
  • Papers
  • Philosophy
  • Philosophy of Academics
  • Philosophy of Science
  • Rebuttals
  • Religion
  • Site News
  • Social Media
The Spiritual Anthropologist
Copyright © 2023 The Spiritual Anthropologist · (in)SPYR Theme by Genesis Developer: SPYR Media