Coordinating movements and beliefs: Different facets of doing things together.

This study investigates the relations between two forms of joint action (JA)-movement coordination (MC) and goal attainment-and theory of mind (ToM), contrasting the interactionist and traditional cognitivist views. A custom task was carried out to measure the properties of the JAs between children and their parents, while classical tasks were performed to measure first- and second-order ToM. Thereafter, cross-recurrence quantification analysis was applied to quantify participants' movements. The children were from Poland and were aged 42, 66, and 78 months (N = 297, 133 girls, White, from a large city). The results suggested that the characteristics of dyad MC influence goal attainment and are related to children's first-order ToM (R²  = .447) but not to their second-order ToM.