IQ is one of the most heavily studied constructs in psychology. Modern IQ tests have over a century of development behind them, starting with Binet and refined through versions like the WAIS-IV and Stanford–Binet. They have high test–retest reliability, meaning a person’s score tends to be stable unless there’s brain injury, illness, or some major change. Scores correlate strongly with academic performance, job performance in cognitively demanding roles, and even certain life outcomes like income, health behaviors, and longevity. There’s also a body of neuroscience work showing links between IQ and measures like processing speed, working memory, and brain connectivity.

The “IQ is BS” meme mostly comes from misunderstandings and misuse. People often assume IQ is meant to measure all kinds of intelligence when it really focuses on certain reasoning and problem-solving skills. Early tests had cultural biases, and while modern versions address this better, that history sticks. It’s also been used for discriminatory purposes, which has left a bad taste even when the measurement itself is valid. Critics are right that IQ doesn’t capture creativity, emotional intelligence, or practical skills—but psychologists never claimed it did.

In short, IQ is a valid and reliable measure for a specific set of cognitive abilities. It’s not the whole story of intelligence, but dismissing it outright ignores a large and consistent body of evidence.