Talk:Human brain size

It is not the size of your brain...

... that matters, but what you do with it.

Some allowance should be made for the size of the body wrapped around the brain - and the capacity it has to manipulate the world in which it operates. Anna Livia (talk) 17:36, 18 March 2019 (UTC)

This page doesn't make an effort to support the claims it makes.

The page makes all sorts of citations (in multiple sections!) to research claiming to demonstrate relationship between brain size and intelligence. However, despite all the times this page claims it's been debunked, there aren't any links to the debunking research- instead there's a link to... a rather bizarre short blog post (Three Toed Sloth).

This RationalWiki page is literally what someone would link to strengthen their claim that brain size is related to intelligence. It actively works against its own goal. It brings up all sorts of things claiming the relationship and virtually nothing to dispute it.

The page would be vastly improved with the inclusion of research actually showing the debunking- perhaps in its own section. Otherwise, one gets the impression that this debunking simply doesn't exist. I certainly wouldn't be able to mount a convincing argument otherwise after reading the page. ^{— Unsigned, by: 115.64.114.253 / talk}

Very dubious claims, the article writer has been trying to discredit this wiki on multiple accounts

The article creator @Jean Lusaz (last activity 18 November 2018) is very likely a sockpuppet of @CBH who has been trying to discredit RationalWiki in a subtle way by posing as a progressive while inserting absolute nonsense into articles. CBH created their account less than 1 week after Lusaz' last activity. Lusaz seemed to abandoned the account after other users were onto him and some of his malicious page creations were deleted. Another IP user has complained about problematic content in the article above.

While not overtly racial in nature, these claims are closely linked to modern scientific racism. Publications alleging such a relationship typically contain citations to hardcore racialists, who in turn cite these publications to advance their own theories. Notable examples of publications alleging relationship between brain volume and intelligence include the following:

A 2002 study by Daniëlle Posthuma, Eco J. C. De Geus, Wim F. C. Baaré, Hilleke E. Hulshoff Pol, René S. Kahn and Dorret I. Boomsma claimed that the relationship between brain volume and IQ is entirely mediated by genetics.[10] This is among the most egregious of such papers, because while it assiduously avoids mentioning race, aside from that omission it is nearly indistinguishable from the racialist arguments about brain volume and intelligence. It is unclear whether Posthuma et al. were oblivious to their claim's ethical implications, or whether the claim was deliberately malicious. A 2010 literature review by Ian Deary, Lars Penke and Wendy Johnson claimed that intelligence is "modest[ly]" correlated with both head size and intracranial volume. However, to quote, "of course, finding correlations does not explain how one variable affects another, and explaining such correlations is considerably more difficult than identifying them." The review includes a section where biases against race, gender, etc. are discussed, and admits "The tools that are currently available to address these issues... are inadequate to resolve them. This is because, at present, we can only measure intelligent performance, which develops over time. Its development in an individual is therefore embedded in the individual’s environment of origin."[11] A 2015 meta-analysis by Jakob Pietschnig, Lars Penke, Jelte Wicherts, Michael Zeiler, and Martin Voracek claimed that intelligence correlates with brain volume. It also claimed that men have larger brains than women, but stopped short of saying that this makes men more intelligent.[12] This paper cites four(!) publications by despised and discredited white nationalist J. Philippe Rushton. The 2015 textbook Experimental Psychology claimed that brain volume correlates with IQ, citing "research" by pseudoscientist Richard Haier.[13] In Stuart Ritchie's 2015 book Intelligence: All that Matters, Ritchie says "There's little reason to doubt that larger brains mean better cognition"[14] and tries to cover his tracks by also saying, "(T)hose with bigger brains have higher IQs. This finding has been highly controversial, but it is now so well established and well replicated that it's pointless to deny it."[15] A 2017 meta-analysis by Gilles Gignac and Timothy Bates claimed that brain volume and IQ have the preposterously high correlation of .40.[16] A 2020 study by Philip R. Jansen, Mats Nagel, Kyoko Watanabe, Yongbin Wei, Jeanne E. Savage, Christiaan A. de Leeuw, Martijn P. van den Heuvel, Sophie van der Sluis and Danielle Posthuma claims to have used a method called genome wide association analysis (GWAS) claims to have found a correlation of 0.24 between polygenic scores for brain volume and intelligence. The authors state in the abstract "These results provide information on the genetics of BV and provide biological insight into BV’s shared genetic etiology with intelligence."[17] A 2019 study by James J. Lee, Matt McGue, William G. Iacono, Andrew M. Michael, and Christopher F. Chabris boldly claims to have found causal evidence of an effect of brain size on IQ. They use within family phenotypic correlations and genome wide association to make these claims. They claim to have found within family spearman rank correlations of about 0.2 between both head circumference and intelligence and brain volume and intelligence. Arthur Jensen is referenced four times in this paper.[18]

These are many studies in reputable scientific journals. Claiming they are "closely linked to modern scientific racism" is obviously absurd. Furthermore several of the authors who are incorrectly linked to scientific racism are outspoken opponents of race and intelligence pseudoscience. Brain Galaxy (talk) 15:11, 17 June 2022 (UTC)

Article should be deleted

Following the mod discussion, I suggest this page is deleted since it was created by a blocked user who was a parody/troll suspected to be Emil Kirkegaard. The article is still filled with BS including calling Haier a "pseudoscientist" and plenty of other inaccuracies. 142.93.41.7 (talk) 18:47, 30 December 2023 (UTC)

Might be wise. The topic is missional and page could be recreated though. Chillpilled (talk) 19:39, 30 December 2023 (UTC)