How Do IQ Tests Work? The Science Behind Intelligence Testing

The Science of IQ Testing

IQ tests are psychometric instruments designed to measure cognitive abilities. They are based on decades of research in psychology and neuroscience.

Test Components

Modern IQ tests typically assess: verbal comprehension, perceptual reasoning, working memory, and processing speed. Each component contributes to the overall IQ score.

Scoring Methodology

IQ scores use a normal distribution with a mean of 100 and standard deviation of 15. Raw scores are converted to standardized scores based on age-matched norms.

Reliability and Validity

Well-designed IQ tests have high reliability (consistent results over time) and validity (they measure what they claim to measure). Test-retest reliability typically exceeds 0.90.

Age Considerations

IQ scores are normalized by age group, meaning a score of 100 indicates average performance for your age. Cognitive abilities develop throughout childhood and typically peak in early adulthood.