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I found this claim on Focus, an Italian pop-sci magazine:

enter image description here

Le reti di connessioni cerebrali nel cervello dei maschi (in alto) e in quelle donne (in basso): in blu sono visibili i collegamenti all'interno dello stesso emisfero, in arancione quelli tra un emisfero e l'altro.

(my translation)

The networks of cerebral connections in the brain of males (top) and in those [sic] females (bottom): same-hemisphere connections are visible in blue, connections across hemispheres are in orange.

It seems extraordinary to me that males have basically only same-hemisphere connections and females only across? Is this image "lying", not showing both types of connections for both genders? The article claims scientific accuracy and to report a scientific paper: does this image represent its conclusions in a fair manner?

It's fairly important to correct any mistakes because this is being repeated by many anti-gay groups (e.g. this or this)

  • 2
    It's fairly well established, I believe, that a typical male brain and a typical female brain have various structural differences. Of course, individual brains vary, and only relatively few are 100% male-structured or 100% female-structured. Does the article in question in fact claim that these particular differences are universally true - 100% of male brains have one structure and 100% of female brains the other? Or does it just leave it to the reader to assume one way or the other? – Harry Johnston Jun 8 '15 at 2:42
  • @HarryJohnston the article only talks about "men" and "women" in general. It never says "most men" or "women, on average, ...". In facts, it says that "the results confirm many stereotypes" :-/ – Sklivvz Jun 8 '15 at 11:37
  • Is what being "repeated" an actual scientific fact of direction of connection, or a more general statement that "male and female brains have structural differences"? I don't read Italian, but I'd be really surprized if it wasn't the latter, given the reason why they'd care about this research. And if it's the latter, in your "important" context, the claim should be stated to be accurate to what those sources claim, not what the article claims (or separated into a separate question, even better) – user5341 Jun 8 '15 at 18:41
  • ... (to clarify: my expectation is that an "anti-gay" group would say something like "sex is 100% clear from biological differences in the brain, so {insert-something-to-support-their-position}". Not "males have intrahemispheric connections and females have interhemispheric, so {insert}"). – user5341 Jun 8 '15 at 18:54
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    @Sklivvz: in the absence of an explicit claim to the contrary, I would generally expect a reasonable person to interpret such a statement as referring to a typical man or woman, not to every man or woman. (After all, if there was evidence that the results did apply universally, that would be astonishing, and worthy of explicit mention.) Of course, you're not dealing with reasonable people, so you need a better argument than that; I'm just suggesting that the confusion may not be entirely the article's fault. :-) – Harry Johnston Jun 8 '15 at 20:09
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Is this image "lying", not showing both types of connections for both genders? The article claims scientific accuracy and to report a scientific paper: does this image represent its conclusions in a fair manner?

Well, it's certainly reporting some of the conclusions correctly. But it's not telling the whole truth.

The article doesn't seem to give the exact name of the study mentioned, but it does name Ragini Verma as leading the study. This supports my original hypothesis that Sex differences in the structural connectome of the human brain is the study cited - Verma is one of the authors.

Quoting from the paper's abstract:

In all supratentorial regions, males had greater within-hemispheric connectivity, as well as enhanced modularity and transitivity, whereas between-hemispheric connectivity and cross-module participation predominated in females. However, this effect was reversed in the cerebellar connections.

This is re-stated later in the paper:

Most supratentorial connections that were stronger in males than females were intrahemispheric (permutation-tested P < 0.05). In contrast, most supratentorial connections that were stronger in females were interhemispheric. However, in the cerebellum, the opposite pattern prevailed, with males showing stronger connections between the left cerebellar hemisphere and the contralateral cortex.

So the claim is really only supported in one region of the brain, not all regions.

Note the phrasing here. It doesn't say that there are more connections between hemispheres in one gender and more connections inside hemispheres in the other gender, but rather that strength is different. Not necessarily number.

The article only tells half of the truth. Consider it untruthful.

The image, by the way, is from Figure 2 of the paper. The caption reads:

Fig. 2. Connection-wise analysis. (A) Brain networks show increased connectivity in males (Upper) and females (Lower). Analysis on the child (B), adolescent (C), and young adult (D) groups is shown. Intrahemispheric connections are shown in blue, and interhemispheric connections are shown in orange. The depicted edges are those that survived permutation testing at P = 0.05. Node color representations are as follows: light blue, frontal; cyan, temporal; green, parietal; red, occipital; white, subcortical. GM, gray matter.

Sections B, C, and D are not shown in the article's use of the image.

  • Are sections B, C and D contradicting the article? E.g. do they show sex-invariant picture? – user5341 Jun 8 '15 at 18:45
  • If I'm reading the paper correctly - and it's way outside my comfort zone - then they are talking about statistical differences, i.e., they are analyzing each group as a whole rather than each individual separately. So the (arguably) implied claim in the article that every male brain has the one structure and every female brain has the other is false. Yes? – Harry Johnston Jun 8 '15 at 19:57
  • @DVK No; they are related to different things. – HDE 226868 Jun 8 '15 at 20:09
  • @HarryJohnston I believe so, yes. – HDE 226868 Jun 8 '15 at 20:10

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