Ask the Experts: Is There a Correlation Between Grades and Intelligence?

Five psychology and education experts share their insights on the complex relationship between academic grades and intelligence. This seemingly straightforward question touches on fundamental debates in educational psychology about what drives academic success and how accurately grades reflect cognitive abilities.

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.

Leehu Zysberg has answered Near Certain

An expert from Gordon College of Education in Education, Psychology

Disclosure:

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.

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.

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”.

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.

Verdict: Yes, Grades and Intelligence Are Correlated, But It’s Not the Whole Story.

All five experts confirm a correlation between grades and intelligence, with correlation values ranging from .25 to .81 depending on the study. However, they emphasize that academic success depends on many additional factors beyond intelligence, including motivation, study habits, teaching quality, and socioeconomic background.

To learn more about cognitive assessment, educational psychology, and intelligence measurement, try searching for related topics on Consensus or check out the questions below.