A nutrition theory of the secular increases in intelligence; positive correlations between height, head size and IQ
Abstract
S ummary . The thesis is advanced that the secular increases in intelligence over the last half century are largely due to improvements in nutrition. These have brought about increases in height, head size and brain size of approximately one standard deviation, about the same magnitude of increase as has taken place in intelligence. The thesis requires the existence of a positive correlation between head size and intelligence. Data for 310 9–10 year‐olds obtained a correlation of +0·21.
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Nutrition, particularly high-quality protein, influences body height, head circumference, and intelligence.
“Improved prenatal and postnatal nutrition may also have contributed to the secular increase in intelligence test scores as nutrition, particularly high-quality protein, influences the makeup of the human body, such as body height, head circumference, and intelligence [20, 23–25] and we observed simultaneous increases in body height and intelligence.”
From The secular trend of intelligence test scores: The Danish experience for young men born between 1940 and 2000 (2021) · cites this paper as [23]
Suboptimal prenatal and postnatal nutrition reduces body height, head circumference, and intelligence, while improvements in nutrition positively influence the human body, including brain development and functioning.
“While suboptimal prenatal and postnatal nutrition has been found to reduce body height, head circumference, and intelligence, improvements in nutrition on the other hand have a positive influence on the human body, including the development and the functioning of the brain [23, 24].”
From The secular trend of intelligence test scores: The Danish experience for young men born between 1940 and 2000 (2021) · cites this paper as [23]
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- Authors
- LYNN, R.
- Affiliations
- University of Ulster (GB)
- Corresponding author
- LYNN, RICHARD
- ORCID
- LYNN, RICHARD
- Venue
- British Journal of Educational Psychology
- Publisher
- Wiley
- Published
- 1989-11
- Volume
- 59
- Issue
- 3
- Pages
- 372-377
- ISSN
- 0007-0998 (ISSN-L)
- 2044-8279
- OpenAlex
- W2076712025
- Cited by
- 71
- References
- 0
- Citations by year
- 2025: 1 · 2023: 2 · 2021: 2 · 2019: 1 · 2018: 1 · 2017: 1 · 2016: 1 · 2015: 5 · 2014: 4 · 2013: 5 · 2012: 4
- FWCI
- 1.41
- Type
- journal article
- Language
- en
- Open access
- closed
- Locations
- British Journal of Educational Psychology (publishedVersion)
- Topics
- Social Sciences › Psychology › Experimental and Cognitive Psychology › Cognitive Abilities and Testing
- Social Sciences › Economics, Econometrics and Finance › Economics and Econometrics › Historical Economic and Social Studies
- Health Sciences › Medicine › Pediatrics, Perinatology and Child Health › Birth, Development, and Health
- Keywords
- nutrition, height, head size, brain size, IQ
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