Vegetarian vs Meat Eater IQ
The vegetarian–IQ connection is one of the most frequently misrepresented findings in popular science. The 2007 British Cohort Study found higher childhood IQ scores among future vegetarians — but the study's authors were clear that this represented IQ predicting diet choice, not diet affecting intelligence. Vegetarians in the UK study were also more likely to be female, of higher social class, and better educated — all factors independently associated with higher IQ. Meanwhile, research on omega-3 fatty acids (DHA and EPA, found primarily in fish and animal products) does show genuine cognitive benefits, complicating the narrative that plant-based diets are cognitively superior.
Vegetarians
Typical range: 102–108
A large UK cohort study (British Cohort Study, n=8,170) found that individuals who became vegetarian by age 30 had IQ scores approximately 5 points higher at age 10 than those who remained meat-eaters. Vegetarians also showed higher educational attainment and social class in this dataset.
Meat Eaters
Typical range: 97–103
The general meat-eating population averages close to the population mean of 100. Omnivore diets that include fish and lean meats provide omega-3 fatty acids, B12, and other brain-essential nutrients — potentially offsetting any diet-related cognitive disadvantage compared to some vegetarian diets.
Key Findings
- The UK British Cohort Study found vegetarians scored approximately 5 IQ points higher at age 10 than those who remained meat-eaters at age 30.
- The causal direction is IQ → diet choice, not diet → IQ: higher childhood intelligence predicted later vegetarianism.
- After controlling for social class, education, and gender, the vegetarian IQ advantage shrinks to approximately 2–3 points.
- Omega-3 fatty acids (DHA/EPA), primarily from fish and animal sources, have genuine brain-supportive effects supported by multiple RCTs.
- Diet quality within any dietary pattern — not the vegetarian/omnivore label itself — is the primary nutritional predictor of cognitive health.
Verdict
A notable 2007 UK cohort study found that childhood IQ predicted later vegetarianism — individuals with higher IQs at age 10 were more likely to adopt vegetarian diets by age 30. The causal direction appears to be IQ → diet choice rather than diet → IQ: smarter people tend to adopt dietary patterns they believe are healthier or more ethical. After controlling for socioeconomic status and education, the IQ difference between vegetarians and meat-eaters shrinks substantially. Diet quality matters far more for cognitive health than the simple vegetarian/omnivore dichotomy.
For more context, see what different IQ scores actually mean and explore famous people's IQ scores.
Frequently Asked Questions
Do vegetarians have higher IQs than meat-eaters?
On average, slightly — approximately 5 points in the largest UK study. However, the relationship runs in the opposite direction from what many assume: higher childhood IQ predicts later adoption of vegetarianism, not vegetarian diets causing intelligence gains. Socioeconomic confounds explain much of the remaining gap.
Does eating meat make you less intelligent?
No evidence supports this claim. Red meat provides B12, zinc, and iron — all brain-essential nutrients. Fish provides DHA and EPA omega-3s that have documented cognitive benefits. What likely matters is overall diet quality, not meat consumption per se.
Can a vegetarian diet harm cognitive development?
Poorly planned vegetarian diets — particularly those lacking B12, omega-3 DHA, zinc, and iron — can impair cognitive development, especially in children and pregnant women. B12 deficiency causes measurable cognitive decline. Well-planned vegetarian diets that address these nutrients through supplementation or fortified foods are nutritionally adequate.
What diet is best for brain health?
The MIND diet — a hybrid of Mediterranean and DASH patterns emphasizing vegetables, berries, whole grains, fish, poultry, olive oil, and nuts — has the strongest evidence for cognitive protection and reduced dementia risk. Neither pure vegetarianism nor omnivory per se predicts better brain health outcomes when overall diet quality is controlled.
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MyIQScores Editorial Team
Researchers in cognitive psychology, psychometrics & educational science
Last updated
May 10, 2026
All content on MyIQScores is reviewed for scientific accuracy against peer-reviewed research in cognitive psychology and psychometrics. Our editorial team cross-references each article with published literature before publication and updates pages whenever new research warrants a revision.