Gignac and Zajenkowski (2020) recommended testing the Dunning-Kruger (DK) hypothesis with a combination of polynomial regression and LOESS regression, as the conventional approach to testing the hypothesis (i.e., quartile split) confounds regression toward the mean and the better-than-average effect. Building upon Gignac and Zajenkowski (2020), an insightful method to estimate the magnitude and prevalence of a DK effect is introduced based on comparing linear and LOESS regression predicted values. Based on simulated data specified to exhibit a plausible DK effect for cognitive abilities, the magnitude of the DK effect was empirically modeled. The effect peaked at a 20-point relative overestimation at an IQ of 55, impacting only 0.14% of the population, and decreased to a 7-point relative overestimation at an IQ of 70, affecting 2.3% of the population. Analysing two large field data samples ( ≈ 3500 each) from participants who completed intelligence subtests in grammar and logical reasoning, the DK effect was found to account for a maximum relative ability overestimation of 7 to 9 percentile points. Notably, this effect was confined to only ≈ 0.2% of the participants (IQ ≈ 55), all of whom scored at chance levels. Finally, low levels of conditional reliability (≈ 0.40) at distribution extremes were found to complicate interpreting results that superficially support the DK hypothesis. It is concluded that, when analyzed using appropriate methods, it is unlikely that the DK effect will ever be demonstrated as an unambiguously meaningful psychological phenomenon affecting an appreciable portion of the population.

中文翻译：

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重新思考邓宁-克鲁格效应：对有限人群的影响可以忽略不计

Gignac 和 Zajenkowski（2020）建议结合多项式回归和 LOESS 回归来检验 Dunning-Kruger (DK) 假设，因为检验假设的传统方法（即四分位数分割）会混淆平均值回归和优于平均值回归- 效果一般。在 Gignac 和 Zajenkowski (2020) 的基础上，基于比较线性和 LOESS 回归预测值，引入了一种富有洞察力的方法来估计 DK 效应的幅度和普遍性。根据指定的模拟数据，对认知能力表现出合理的 DK 效应，对 DK 效应的大小进行了经验建模。当智商为 55 时，该效应达到峰值，相对高估 20 点，仅影响 0.14% 的人口；当智商为 70 时，相对高估相对下降 7 点，影响 2.3% 的人口。通过分析来自完成语法和逻辑推理智力分测试的参与者的两个大型现场数据样本（每个样本约 3500 个），发现 DK 效应可以解释最大相对能力高估 7 到 9 个百分点。值得注意的是，这种效应仅限于约 0.2% 的参与者（智商约 55），所有参与者的得分都是偶然的。最后，分布极值条件可靠性水平较低（约 0.40），这使得表面上支持 DK 假设的解释结果变得复杂。结论是，当使用适当的方法进行分析时，DK 效应不太可能被证明是一种影响相当大一部分人口的明确有意义的心理现象。