Acting and Practising Together: Modulations of the Joint Simon Effect in 6- to 8-Year-Old Children

The study investigated joint action performance and joint unintentional transfer of learning in two cohorts of elementary school children. Thirty-two first-graders (mean age 6.6 ± 1.22 years; 22 females; all White) and 32 second-graders (mean age 7.8 ± 0.27 years; 15 females; all White) performed a Joint Simon task before and after performing a joint spatial compatibility task in which stimulus position was mapped incompatibly to the response position. We assessed whether, prior to training, children displayed a reliable Joint Simon effect (JSE), indicative of co-representation, and whether age-related differences emerged in its magnitude. Furthermore, we assessed whether the effect was affected by a jointly performed practice. Both age groups showed a significant JSE that was eliminated by the joint incompatible practice. No significant age-related differences emerged. Our results indicate that 6- to 8-year-old children are influenced by the presence of another agent and suggest that the knowledge acquired during joint task performance may automatically and unintentionally transfer to a subsequent similar task.