Are IQ Scores a Good Predictor of General Intelligence?

Are IQ scores a good predictor of general intelligence?

Check out this answer from Consensus:

IQ scores are a strong but imperfect predictor of general intelligence. They correlate with brain structure, genetic and environmental factors, and can predict various cognitive and real-world outcomes. However, their use as covariates in research and the generalizability of score gains remain contentious. Future research should continue to explore the complexities of IQ and general intelligence to provide a more comprehensive understanding of cognitive abilities.

The question of whether IQ scores are a good predictor of general intelligence has been a topic of extensive research and debate. IQ tests have been widely used to measure cognitive abilities and predict various life outcomes, but their effectiveness in capturing the full spectrum of general intelligence, often referred to as “g,” remains under scrutiny. This article explores the relationship between IQ scores and general intelligence by reviewing findings from multiple research studies.

The Relationship Between Brain Structure and IQ

Research has shown that brain structure, particularly total brain volume and specific regions of interest (ROIs), correlates with IQ scores. A study using voxel-based morphometry (VBM) identified significant gray matter correlates of IQ in various Brodmann areas, including the frontal, temporal, parietal, and occipital lobes1. These findings suggest that the neural basis of intelligence is distributed across multiple brain regions, indicating a complex relationship between brain structure and IQ.

Genetic and Environmental Influences

General intelligence has a substantial genetic component, but environmental factors also play a crucial role. A study involving 1475 adolescents found that general IQ is associated with functional brain activation, a polygenic score for intelligence, and epigenetic markers for dopamine neurotransmission2. This highlights the malleability of IQ and the importance of both genetic and environmental influences on cognitive performance.

IQ as a Measure of Psychometric “g”

IQ scores are often used as indicators of psychometric “g,” the general factor of intelligence. A study using joint confirmatory factor analysis found that IQs have high correlations with general factors representing psychometric “g,” with g loadings ranging from .88 to .953. This suggests that while IQ scores are strong indicators of general intelligence, they are not perfect and may not capture all aspects of cognitive ability.

Predictive Validity of IQ

IQ scores have been shown to predict performance on various cognitive tests and real-world outcomes. For instance, a study found that IQ predicts neuropsychological test performance across the entire spectrum of intelligence, although the predictive power is stronger among individuals with average or below-average IQ4. Another study demonstrated that general intelligence is the best predictor of income, social status, and educational attainment, even beyond other cognitive performance measures5.

Limitations of IQ as a Covariate

Despite their widespread use, IQ scores have limitations, particularly when used as covariates in cognitive studies. One study argued that IQ scores are volatile indices influenced by a range of factors, including genes, biology, education, and experiences6. The study cautioned against using IQ as a covariate, as it may lead to overcorrected and counterintuitive findings in neurocognitive research.

Score Gains and Generalizability

IQ scores can be increased through retesting and cognitive interventions, but these gains do not necessarily reflect improvements in general intelligence. A meta-analysis of test-retest studies found that score gains are not related to the g component of intelligence, suggesting that the generalizability of test scores resides predominantly in the g component7. This indicates that while IQ scores can improve, these improvements may not translate to broader cognitive abilities.

Are IQ scores a good predictor of general intelligence?

Robert Sternberg has answered Likely

An expert from Cornell University in Education, Intelligence, Development Studies, Psychology

IQ scores are a measure of so-called “general intelligence,” but the real problem is that general intelligence as it has traditionally been defined is not so general. It does not take into account creative intelligence, practical intelligence (common sense), emotional intelligence, social intelligence, or wise uses of intelligence. 

As a society, we have made a stupid mistake by over-weighing not only tests of intelligence, but their proxies, such as SATs, ACTs, GREs, and the like. These tests do NOT measure our skills in solving important life problems. Look at all the high-IQ geniuses who have contributed to air pollution, water pollution, global climate change, overuse of antibiotics, weapons of mass destruction, and on and on. If those people are smart, why is humanity extinguishing itself by creating an environment that will be awful for our children, grandchildren, and beyond. If creating a world that is impossible to live in is intelligent, then the word has truly lost its head. Intelligence is about the “ability to adapt to the environment,” not to destroy it.

Are IQ scores a good predictor of general intelligence?

Vittorio Daniele has answered Likely

An expert from University Magna Graecia in Macroeconomics, Economics

Yes, IQ test scores are a good proxy of general intelligence, if intelligence refers to abstract and logical reasoning. 

Are IQ scores a good predictor of general intelligence?

Louis Matzel has answered Near Certain

An expert from Rutgers University in Genetics, Psychology, Neuropsychology

Most common IQ tests are good predictors of general intelligence. To appreciate this, we must ask how we expect intelligence to exert itself in our natural environments. For instance, it is reasonable to expect that more intelligent individuals will obtain more education, achieve better grades, have higher incomes, be healthier, happier, attain higher social status, be less likely to develop a drug addiction, and be generally more effective in their chosen occupations. (This list could be expanded to included hundreds of such predictors of life success.) So the question is, does an IQ test that is administered to a young child predict these later life outcomes that we believe are indicative of intelligence. The answer to this question is an overwhelming “yes”. IQ tests have enormous predictive capacity. I often hear from students that “IQ tests only measure test-taking ability” (something that they probably heard from a professor who was not familiar with the actual data). While this may be true in part (after all, every day is a test), it is overwhelmingly clear that performance on an IQ test predicts life outcomes that go well beyond what can be captured on a simple paper and pencil test.

Are IQ scores a good predictor of general intelligence?

Vincenzo Varriale has answered Near Certain

An expert from Sapienza University of Rome in Intelligence, Psychometrics

Yes, the IQ score is the most valid predictor of intelligence level and academic achievement in adulthood, even when performed in primary school-age.

(i.e. see Mayes et al. (2009) IQ and neuropsychological predictors of academic achievement, Learning and Individual Differences,19(2), 238-241, https://doi.org/10.1016/j.lindif.2008.09.001).

Are IQ scores a good predictor of general intelligence?

Andreas Demetriou has answered Near Certain

An expert from University of Nicosia in Intelligence, Cognitive Science

IQ scores are accurate predictors of general intelligence, accounting for about 50% of its variance. The cognitive functions represented in modern IQ tests, such as working memory, inference, and environment-relevant knowledge, are important components of general intelligence.

Are IQ scores a good predictor of general intelligence?

Carmen Flores-Mendoza has answered Likely

An expert from Federal University of Minas Gerais State in Intelligence

If we understand that IQ is a metric that we use to quantify cognitive performance, we can infer that assessing general intelligence depends more of the quality of cognitive ability/intelligence tests. For instance, a battery of four tests measuring concentrated attention, digit symbol, digit span, and object assembly probably is not a strong predictor of general intelligence. On the other hand, a battery measuring abstract reasoning, spatial reasoning, vocabulary, information is likely a strong predictor of general intelligence.

The g Factor written by Arthur Jensen provides an excellent explanation regarding general intelligence.