According to a recent study from Linköping University, while individuals with higher incomes tend to score better on IQ tests, there is a limit to this trend. Beyond a certain income level, the correlation between income and IQ test scores levels off, and, in fact, the top 1% of earners may even score slightly lower on the tests than those in the income bracket just below them. This finding indicates that it is not possible to equate high income with high intelligence.
The researchers utilized wage data from the Swedish population alongside scores in cognitive tests that were mandatory among military conscripts.
“This data trove permits us to test, for the first time, whether extremely high wages are indicative of extreme intelligence. To do so, we needed reliable income data that covers the entire wage spectrum,” the researchers explain. “Survey data typically miss top incomes, but the registers offer full income data on all citizens.”
A tenuous link
The link between cognitive ability and salary is significant for most people at all salary levels. However, when salaries reach a certain threshold, salary no longer plays a role in separating individuals based on their cognitive abilities.
According to the researchers, when annual salaries reach €60,000, average cognitive ability levels off at a modest +1 standard deviation. Surprisingly, the top 1% of earners actually score slightly lower on cognitive ability tests than those in the income group just below them. This is a significant discovery in light of the growing debate surrounding rising income inequality.
Many people defend the high salaries of top earners by claiming that their exceptional talents justify their large salaries. However, this study finds no evidence to support this argument, as cognitive ability – a key aspect of merit – does not seem to play a role in determining salaries in the top income bracket.
For most citizens, salaries are directly linked to their cognitive abilities. However, among the highest earners, cognitive abilities do not appear to influence salaries. Additionally, differences in occupational prestige – another indicator of job success – among professionals such as accountants, doctors, lawyers, professors, judges, and politicians do not seem to be related to their cognitive abilities. The researchers note that with the steady increase of top earners in Western countries, a growing portion of total income may be allocated in ways that are unrelated to cognitive capability.
