Whether any one test can measure a concept as complex as intelligence has been a topic of considerable controversy. What we do know is that the WAIS does a good job of measuring a range of cognitive skills that are indicators of other measures of intelligence, such as academic and occupational success. WAIS subtests are also well correlated with many other cognitive tests and with studies on brain activity. In other words, compared with those who have lower scores, people with high scores on the WAIS are more likely to perform well in school and in their work life and to score well on other tests of thinking ability. They are also more likely to show greater activity in the areas of the brain associated with complex thought.