Is There a Correlation Between Grades and Intelligence?

Is there a correlation between grades and intelligence?

Is there a correlation between grades and intelligence?

Check out this answer from Consensus:

The correlation between intelligence and grades is evident, with intelligence being a strong predictor of academic achievement. However, this relationship is nuanced and influenced by various factors, including personality traits, prior academic performance, gender, and sustained attention. Understanding these factors can help in developing educational strategies that cater to individual differences, potentially enhancing academic outcomes for students.


The relationship between intelligence and academic performance has been a subject of interest for educators, psychologists, and researchers for many years. Intelligence is often considered one of the most significant predictors of academic success. This article examines the correlation between standardized intelligence tests and school grades, exploring how this relationship varies across different domains, grade levels, and individual differences such as personality traits and motivation.

Intelligence as a Predictor of Academic Achievement

A meta-analysis of 240 independent samples involving over 100,000 participants found a significant population correlation (ρ = .54) between standardized intelligence tests and school grades1. This correlation suggests that intelligence is a strong predictor of scholastic achievement. Similarly, a longitudinal study of Portuguese middle school students revealed that intelligence is a better predictor of academic achievement when considering the mediation effect of prior academic performance2. Moreover, a 5-year prospective longitudinal study of English children showed that general intelligence at age 11 was highly correlated (0.81) with educational achievement at age 16 across 25 academic subjects4.

The Role of Personality Traits

Personality traits also play a role in predicting academic success. A study involving British university students found that personality traits, particularly Conscientiousness, accounted for additional variance in statistics examination grades over and above psychometric intelligence3. In Estonian schoolchildren, intelligence was the strongest predictor of grade point average (GPA), but Agreeableness and Conscientiousness also correlated positively with GPA5. These findings suggest that while intelligence is a significant factor, personality traits contribute to academic performance as well.

Gender Differences and Subject-Specific Achievement

Gender differences in academic achievement were not attributed to differences in general intelligence. Girls performed significantly better on all subjects except Physics, which was not due to their better verbal ability4. In Austrian eighth graders, intelligence and ability self-perceptions were the strongest predictors of grades, with additional predictors such as Conscientiousness and Neuroticism in Math, and an interaction between sex and Extraversion in German and English9.

The Moderating Role of Sustained Attention

The relationship between intelligence and academic achievement might be moderated by sustained attention. A study of 11th and 12th grade students found that sustained attention scores were related to school performance and moderated the relationship between intelligence and grades in specific subjects10.


Is there a correlation between grades and intelligence?

Michael O’Connell has answered Near Certain

An expert from University College Dublin in Psychology

In relation to the question on a correlation between school grades and intelligence, the following is a quote from a paper by Ian Deary et al, in 2007, (volume 35, issue 1, pp. 13-21) in the journal Intelligence:

“What, then, is the association between cognitive ability and educational achievement? There is broad agreement that there is a moderate to strong correlation between the two. Jencks et al.’s (1979, p. 102)detailed account of eight samples from six longitudinal studies reported correlations ranging from 0.40 to 0.63 between cognitive test scores and amount of education obtained. More recent overviews are provided by various authors and reach similar conclusions (Bartels et al., 2002b, Brody, 1992, Jensen, 1998, Neisser et al., 1996, Sternberg et al., 2001). For example, Mackintosh’s (1998) survey reckoned that there is a correlation between 0.4 and 0.7 between IQ scores and school performance grades. More specifically for the present study, Mackintosh stated that, “in Britain, the correlation between 11-year-old IQ scores and later educational attainment, including performance on school examinations at age 16, is about 0.5”.

The 2007 paper by Deary et al examining the relationship between academic grades and measured intelligence among a sample of 70,000 Scottish secondary students reported a strong correlation of 0.81.

So overall, there is consistent evidence of a moderate to strong correlation between academic grades and measured intelligence.


Is there a correlation between grades and intelligence?

Leehu Zysberg has answered Near Certain

An expert from Gordon College of Education in Education, Psychology


The short answer to this question is OH YES ! Intelligence is basically the best single predictor of academic attainment throughout the lifespan, as well as work performance! a few seminal reviews have established that much as far as 25 years ago and these results remained stable ever since. The longer answer is – yes, but not always. Culture, learning disabilities and even gender may play a major role in predicting academic grades in various settings on one hand while on the other – intelligence measures are deeply biased by the very same factors. Another field of research that shown huge associations with academic outcomes is the field of motivation and perceived ability (aka – self efficacy). Last but not least – socioeconomic status has shown moderate yet very stable association with academic attainment, especially in K-12 settings but also in academic ones.


Is there a correlation between grades and intelligence?

Brenda Hannon has answered Likely

An expert from Texas A&M University in Cognitive Science

Yes, but it is important to not confusion the relationship between amount of education and intelligence with the relationship between grades and intelligence. Because I believe the magnitude of the correlation is quite difference between these two relationships.

With respect to grades and intelligence, the correlation is about .25 to .35… significant but modest. To be successful with academics there is a need to understand how to learn. Self-efficacy and persistence are also important to successful academics.


Is there a correlation between grades and intelligence?

Hynek Cígler has answered Near Certain

An expert from Masaryk University in Psychology, Quantitative Psychology, Psychometrics, Intelligence

Of course! This relation is observed in any research with intelligence test involving the grades.

But unfortunately, the relation between the intelligence and grades is only probabilistic and it depends on many other influences, like the social status, income, race and stereotypes (or sex and stereotypes) etc. If you cannot spend a lot of time studying, or if the study is not valued in your family, you obviously wouldn’t have good grades. On the other hand, grades are also dependent on many other traits, like your motivation, conscientiousness etc. Even if you are not really smart, with a huge motivation you can learn a lot and be “excellent student”.


Is there a correlation between grades and intelligence?

Gavin Brown has answered Near Certain

An expert from University of Auckland in Education, Psychometrics, Statistics

the correlation is about .25 between IQ and school achievement. The reason it is so low is that smart kids do dumb things (e.g., drugs, not attend, don’t try, etc.), while kids with somewhat lower IQ can do the opposite for a variety of reasons. Also the child’s IQ is independent of the quality of teachers and schools–in other words excellent teachers and curriculum can raise achievement, while skill-and-drill teaching can lower it. Good sources on this topic include:

Martinez, M. E. (2000). Education as the Cultivation of Intelligence. Mahwah, NJ: LEA.

Neisser, U., Boodoo, G., Bouchard Jr., T. J., Boykin, A. W., Brody, N., Ceci, S. J., . . . Urbina, S. (1996). Intelligence: Knowns and unknowns. American Psychologist, 51(2), 77-101.

Deary, I. J. (2001). Intelligence: A Very Short Introduction. Oxford, UK: OUP.

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