By Cate Chapman, Editor at LinkedIn News — Just how much is a person’s salary related to their cleverness? Well, smarts and higher earnings are related, but only up to a point, new research published in the European Sociological Review reports. Higher general intelligence correlated with wages — up to an annual salary of $57,300, the study of almost 60,000 Swedish men found. But after that point, ability flattened out as wages continued to increase.

Earners in the top percentile even scored lower on verbal, technical, spatial and logic tests than those immediately below them. The study’s authors see a warning sign for societies amid growing income inequality. Non-cognitive abilities, including motivation and social skills, weren’t accounted for in the study.