No indication that the ego depletion manipulation can affect insight: a comment on DeCaro and Van Stockum (2018)

Abstract Recently, DeCaro and Van Stockum have suggested that ego depletion following intensive self-control can improve insight problem-solving; this finding was interpreted in terms of insight relying on decreased control over attention and memory. However, DeCaro and Van Stockum used three variants of the single matchstick arithmetic problem. Experiment 1 involved low sample and non-standard problem application, while the more powered Experiment 2 yielded a surprisingly low solution rate. These facts made both studies problematic and called for their replication. In the two present studies, the DeCaro and Van Stockum ego-depletion manipulation and their matchstick problems were administered to a total of 316 people. Furthermore, various other insight problems, subjective ratings of insight experience, analytical problems and executive control tests were applied. The key result was that no reliable effect of ego depletion could be found for any of these measures.