It pays to be smart, or so the saying goes. But the biggest earners may not be the workers who are the brainiest, according to one recent Swedish study.

The research, published in the European Sociological Review in January, found that higher general intelligence was correlated to higher wages — but only up to a threshold of about 600,000 Swedish krona ($57,300) a year. Beyond that point, the study found that ability plateaus as wages continue to rise. And earners in the top 1% score slightly worse than those in the income tier directly below them.

"We find no evidence that those with top jobs that pay extraordinary wages are more deserving than those who earn only half those wages,” wrote the authors of the study, which was led by Marc Keuschnigg, a senior associate professor for analytical sociology at Linkoping University in Sweden.