The cognitive reflection test (CRT) is a task designed to measure a person's tendency to override an incorrect "gut" response and engage in further reflection to find a correct answer. However, the validity of the assessment as a measure of "cognitive reflection" or "intuitive thinking" is under question. It was first described in 2005 by psychologist Shane Frederick. The CRT has a moderate positive correlation with measures of intelligence, such as the IQ test, and it correlates highly with various measures of mental heuristics. Some researchers argue that the CRT is actually measuring cognitive abilities (colloquially known as intelligence).
Later research has shown that the CRT is a multifaceted construct: many start their response with the correct answer, while others fail to solve the test even if they reflect on their intuitive first answer. It has also been argued that suppression of the first answer is not the only factor behind the successful performance on the CRT; numeracy and reflectivity both account for performance.