The Problem With IQ Tests

IQ is ubiquitous in popular culture, from casual conversations to job requirements. People frequently reference IQ scores and use IQ-related terminology in everyday language.

People commonly understand IQ as an objective, rigorous measurement of intellectual ability.

• Where did IQ testing originate • What does IQ actually measure • What can IQ predict about life outcomes • What is the presenter's own IQ score

The presenter expresses doubt about online IQ tests and plans to take an official test after practice, though believes the test itself may be trainable.

In 1904, Charles Spearman observed that students performing well in one subject tended to perform well in other subjects, finding a correlation coefficient of 0.64 between math and English scores.

Spearman proposed that each person possesses a general intelligence factor (g-factor) that determines performance across all subjects, representing the ability to learn new material, recognize patterns, and think critically regardless of subject matter.

Alfred Binet and Theodore Simon developed the Binet-Simon test in France to identify students needing academic help, using tasks like identifying missing objects, defining terms, and repeating sentences.

The intelligence quotient was calculated by dividing mental age by actual age and multiplying by 100, creating the first standardized IQ test.

The Binet-Simon test was translated to English by Goddard and brought to the United States, where Lewis Terman at Stanford standardized it with American samples, creating the Stanford-Binet test.

Many IQ tests were subsequently developed, all designed to measure the g-factor by assessing multiple mental abilities including memory, verbal, spatial, and numerical skills.

• Tests were administered to large population samples to standardize scoring • Raw scores were normalized with a mean of 100 and standard deviation of 15 • 68% of people score between 85 and 115 • Only around 2% score above 130 or below 70

IQ tests contain 7-10 sections with distinct tasks to minimize subject-specific distortions and average out these effects to approximate general intelligence.

Tests include word matching questions requiring selection of similar meanings or opposite meanings from multiple choice options.

• Identify missing numbers in sequences by analyzing differences between adjacent terms • Recognize ratios between consecutive numbers • Find the logical next term using mathematical relationships

Three-by-three grids with symbols follow predictable patterns including translational motion, rotational motion, missing symbols, and addition operations where overlapping lines cancel out.

Most modern IQ tests require completion under time constraints, allowing only 10-30 seconds per question.

IQ scores show strong correlation with school success. A 2007 study of 13,000 British 11-year-olds found their IQ scores correlated at 0.8 with national school examination results five years later, meaning 66% of variation in exam scores could be predicted by prior IQ tests.

The SAT, ACT, and GRE tests correlate with standard IQ tests at approximately 0.8, functioning essentially as IQ tests.

IQ predicts job success with typical correlations ranging from 0.2 to 0.6, with strongest effects for technical or high-complexity positions, measured through boss ratings, income, and productivity metrics.

The U.S. military prohibits enlistment for those with IQ below 80 and limits to 20% the number of recruits with IQs between 81-92, as lower IQ individuals fail training at 1.5-3 times higher rates.

A 2005 meta-analysis found a correlation of 0.33 between IQ and brain size, supporting the concept of 'big brain' associated with higher intelligence.

A Scottish study tracking children from age 11 to 76 found that for every 15-point increase in IQ, individuals were 27% more likely to still be alive at age 76, confirmed by meta-analysis showing higher IQ correlates with lower mortality risk.

Higher IQ generally correlates with increased income, but a meta-analysis of 31 studies found only a 0.21 correlation between IQ and income, meaning just 4.4% of income variance is explained by IQ.

The relationship between IQ and net worth is even weaker than with income, suggesting that high intelligence does not necessarily translate to wealth accumulation despite higher annual earnings.

In France, Binet believed intelligence could be improved through education and designed tests to help struggling students. In the U.S., the test was modified to rank adults by intelligence, reflecting beliefs that g was unchangeable and inherited.

Henry Goddard used claims about inherited, unchangeable intelligence to support the American eugenics movement, which sought to prevent those with undesirable traits from reproducing.

• Many states passed laws enabling forced sterilization based on IQ test thresholds • The U.S. Supreme Court upheld these laws in 1927 • Over 60,000 people were forcibly sterilized as a result • These laws served as a model for Nazi Germany

Scientific terms like 'moron,' 'idiot,' and 'imbecile' were used as diagnostic categories but became insults, reflecting the prejudicial application of IQ testing.

IQ is not entirely determined by genetics. Twin studies suggest approximately 50% heritability and 50% environmental influence, though estimates range between 40-70% depending on methodology.

Intelligence is not completely fixed over a lifetime, as education can improve IQ scores.

• Fluid intelligence: ability to learn, process information, and solve novel problems • Crystallized intelligence: accumulated knowledge over lifetime • Both increase during childhood but fluid intelligence peaks in early adulthood and declines • Crystallized intelligence remains more stable throughout life

Identical twins show very strong correlation in IQ scores, similar to the same person tested weeks apart.

The presenter reports the test felt fair with multiple diverse sections. The math section was particularly easy, with time limits being the most challenging aspect.

• Quantitative score: 143 (blew the roof off this section) • Crystallized intelligence index: 132 • Fluid intelligence index: 118 (higher than 88.5% of population) • Overall g-factor estimate: 134 (higher than 98.8% of population)

The presenter credits practice and training with improving performance, noting that motivation was likely higher than average due to pride in test-taking ability.

The psychologist notes that different tests may produce different results, and individual strengths and weaknesses exist even at high IQ levels.

Articles claim observed gaps between average IQ of Black and White Americans, and report purported average national IQs below 70, suggesting genetic differences between races.

Researcher James Flynn found that average IQ test scores increased steadily over the past century by approximately 30 points total, requiring tests to be re-normalized every several years to maintain a mean of 100.

• Improved childhood nutrition and health (height also increased similarly) • Better access to education and school quality • Shift from manual labor to abstract thinking work over the century • Population becoming better at answering IQ test question types

Since population genetics haven't changed over a century, the massive IQ increase demonstrates that cultural and environmental changes significantly affect test scores, suggesting cultural differences between contemporary groups have similar effects.

Tests labeled 'culture fair' are marketed as equally valid for all cultures, but it is impossible to construct completely culture-free or culture-fair tests—the label is fundamentally a marketing term.

• Cultures differ in whether they have words for shapes or spatial relations • These linguistic differences influence how people categorize and think about visual information • Cultures without printed materials may perceive them differently than Western cultures

Culture-fair tests ignore forms of intelligence important for survival in other cultures, such as ethnobotanical knowledge, training dogs to hunt, or surviving alone in the rainforest.

Stringent requirements exist before tests validated for one population can be used with very different populations, yet many tests are applied across diverse groups without adequate validation.

Financial incentives significantly increase IQ scores in studies. Offering $1 produces modest increases, $1-10 produces larger increases, and amounts over $10 can increase scores by up to 20 points, with largest effects for below-average IQ individuals.

Coaching and training for IQ tests can boost scores by up to 8 points, making the tests partially trainable rather than purely measuring innate ability.

• Some people perform better under time pressure than others • Knowing when to skip questions affects final scores • Ability to eliminate wrong answers efficiently impacts results • Strategic guessing when uncertain improves performance

Small amounts of anxiety can be beneficial, but excessive anxiety negatively impacts IQ test performance.

In forensic neuroscience, IQ tests serve an important function in death penalty cases through the Atkins defense, which protects individuals with intellectual disability from capital punishment.

Modern IQ tests include embedded measures of invalidity detectable through mathematical algorithms, achieving over 95% accuracy in detecting individuals attempting to fake poor performance.

Boosting cognitive ability early in life could help people reach functional independence longer, even as they age and experience cognitive decline, providing practical benefits for daily tasks.

Using objective IQ tests for gifted program placement increases enrollment of poorer children and minority ethnic backgrounds compared to subjective teacher recommendations, reducing socioeconomic bias.

Psychology and the public maintain complex, contradictory attitudes toward IQ testing, with many people wanting to know their scores while simultaneously dismissing the importance of the measurement.

• One extreme: IQ is the most important factor and should determine educational classification • Other extreme: IQ tests are completely useless and only perpetuate racism and prejudice • Both extremes are unproductive and ignore moderate views

IQ tests provide meaningful information about certain cognitive abilities but don't determine someone's worth or how their life will turn out, and moderate perspectives are often overlooked in polarized debates.

What truly matters more than IQ score is how one interacts with and helps people around them. While IQ tells us something, dramatic improvements in life outcomes come from building knowledge and analytical skills.

Despite appearing objective, IQ tests do not measure what many believe they measure. They are influenced by culture, time period, education, and various psychological factors beyond general intelligence.

• Tests are culturally influenced and change in validity over time • Motivation, training, anxiety, and test-taking strategy affect scores • Tests measure specific cognitive skills, not innate ability or potential • Genetic component is moderate, not deterministic

Openness to experience is the only personality trait correlating with IQ. Greater willingness to try new things leads to more learning and increased intelligence.

While IQ tests have legitimate uses in specific contexts, they should not be treated as definitive measures of intelligence, worth, or potential. Personal agency and continuous learning are more powerful determinants of life success.