Updating is the executive function (EF) previously found to most strongly relate to higher cognitive abilities such as reasoning. However, this relationship could be a methodological artifact: Measures of other EFs (i.e., inhibition and shifting) usually isolate the contribution of EF, whereas updating is measured by overall accuracy in working memory (WM) tasks involving updating. This updating accuracy-score conflates updating-specific individual differences (e.g., removal of outdated information) with variance in WM maintenance. Re-analyzing data (N = 111) from von Bastian et al. (2016), we separated updating-specific variance from WM maintenance variance. Updating contributed only 15% to individual differences in performance in the updating tasks, and it correlated neither with reasoning nor with independent WM measures reflecting storage and processing or relational integration. In contrast, the WM maintenance component of the updating task correlated with both abilities. These findings challenge the view that updating contributes to variance in higher cognitive abilities.

The worst performance rule describes the often-observed phenomenon that individuals' slowest responses in a task are more predictive of their intelligence than their fastest or average responses. To explain this phenomenon, Larson and Alderton (1990) suggested that occasional lapses of attention might result in slower reaction times. Because less intelligent individuals are more likely to experience lapses of attention, they should show a more heavily skewed reaction time distribution, causing an increase in correlations between reaction times and intelligence across the percentiles of the distribution. The attentional lapses account has been well-received, not least because of to its intuitive appeal, but has never been subjected to a direct empirical test. Using state-of-the-art hierarchical modeling approaches to quantify and test the worst performance rule, we investigated in a sample of 98 participants if different behavioral, self-report, and neural measures of attentional control accounted for the phenomenon. Notably, no measure of attentional lapses accounted for increasing covariances between intelligence and reaction time from best to worst performance. Hence, our results challenge the attentional lapses account of the worst performance rule.