•Conventional tests of the Dunning-Kruger hypothesis are shown to be confounded. •The Glejser test is argued to be a valid test of the Dunning-Kruger hypothesis. •Nonlinear regression is argued to be a valid test of the Dunning-Kruger hypothesis. •Failed to identify the Dunning-Kruger effect with IQ data and both valid tests. The Dunning-Kruger hypothesis states that the degree to which people can