Are Bigger Brains Smarter? Evidence from a Large-Scale Pre-Registered Study

20 Pages Posted: 21 Dec 2018

See all articles by Gideon Nave

Gideon Nave

University of Pennsylvania - The Wharton School

Wi Hoon Jung

Korea University; University of Pennsylvania

Richard Karlsson Linnér

Vrije Universiteit Amsterdam

Joe Kable

University of Pennsylvania

Philipp Koellinger

Vrije Universiteit Amsterdam

Date Written: December 3, 2018

Abstract

A positive relationship between brain volume and intelligence has been suspected since the 19th century and empirical studies seem to support this hypothesis. However, this claim is not uncontroversial because of concerns about publication bias and the lack of systematic control for critical confounding factors (e.g., height, population structure). We performed a pre-registered study of the relationship between brain volume and cognitive performance in a new adult population sample from the UK that is about 70% larger than all previous investigations on this subject combined (N=13,608). Our analyses systematically controlled for sex, age, height, socioeconomic status and population structure, and is free of publication bias. We find a robust association between total brain volume and fluid intelligence (r=0.19), which is consistent with previous findings in the literature after controlling for measurement quality of intelligence in our data. We also find a positive relationship with educational attainment (r=0.12). These relationships are mainly driven by grey matter (rather than white matter or fluid volume) and effect sizes are similar for both sexes and across age groups.

Keywords: intelligence, educational attainment, brain volume, pre-registered analysis, UK Biobank

Suggested Citation

Nave, Gideon and Jung, Wi Hoon and Karlsson Linnér, Richard and Kable, Joe and Koellinger, Philipp, Are Bigger Brains Smarter? Evidence from a Large-Scale Pre-Registered Study (December 3, 2018). Available at SSRN: https://ssrn.com/abstract=3295349 or http://dx.doi.org/10.2139/ssrn.3295349

Gideon Nave

University of Pennsylvania - The Wharton School ( email )

3730 Walnut St
JMHH Suite 700
Philadelphia, PA 19104-6365
United States

Wi Hoon Jung

Korea University

1 Anam-dong 5 ka
Seoul, 136-701
Korea, Republic of (South Korea)

University of Pennsylvania

Philadelphia, PA 19104
United States

Richard Karlsson Linnér

Vrije Universiteit Amsterdam ( email )

De Boelelaan 1105
Amsterdam, ND North Holland 1081 HV
Netherlands
+31633226460 (Phone)

HOME PAGE: http://ctg.cncr.nl/about-us/richard_karlsson_linner

Joe Kable

University of Pennsylvania

Philadelphia, PA 19104
United States

Philipp Koellinger (Contact Author)

Vrije Universiteit Amsterdam ( email )

De Boelelaan 1105
Amsterdam, ND North Holland 1081 HV
Netherlands

HOME PAGE: http://www.philipp-koellinger.com

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