The effect of post-success handwashing on insight problem solving

Handwashing, as a common physical cleansing behavior, not only serves a physiological cleaning function but is also believed to symbolically "wash away" emotional experiences or mental residues. Previous research has primarily focused on the regulatory effects of handwashing on failure, negative emotions, or moral judgments, while its role in emotional regulation after success experiences and its influence on creative cognition (such as insight problem solving) remain unclear. Grounded in embodied cognition theory and the broaden-and-build theory, this study experimentally manipulated success experiences and handwashing behavior to examine the regulatory effect of handwashing on positive emotions induced by success and its influence on insight-related problem solving. The experiment initially recruited 96 undergraduate students, who were randomly assigned to a handwashing group, a non-handwashing group, and a control group; the final analyzed sample consisted of 87 participants after applying exclusion criteria. The results showed that: (1) Handwashing significantly reduced the positive emotions induced by success, serving as an "emotional reset"; (2) Participants in the success conditions responded significantly faster in the Chinese Compound Remote Associates Test (CCRA) than those in the control condition; however, no significant group differences were observed in overall solution accuracy, indicating that the effect of success experience was reflected primarily in problem-solving efficiency rather than a general improvement in insight problem-solving performance; (3) In insight solutions, no significant difference in accuracy was found between the handwashing and non-handwashing groups. However, accuracy in the handwashing group was significantly lower than in the control group. An opposite pattern was observed for non-insight solutions. These findings indicate that handwashing functions as a form of emotional regulation after success and may attenuate the carryover of success-induced positive emotions that support insight-related processing, although this effect should be interpreted with caution. This study extends the research scope of the "symbolic handwashing effect" and provides new experimental evidence for understanding the relationship between positive emotion regulation and creative thinking.