This dataset was collected between November 2021 and March 2022 as part of the Joint Action in Sports and Social Learning Project at the University of Konstanz. It includes multimodal recordings from 70 participants performing both individual- and joint-action ball-hitting tasks. Data comprise body kinematics (motion capture), eye movements (Tobii Glasses), and heart rate (ECG), complemented by questionnaire responses. Processed files include event-level features (e.g., anticipatory saccades, swing timing, contact dynamics), motion energy, and ECG summaries, while raw session folders provide cleaned trial-level recordings. The dataset is structured to reproduce the analyses reported in “Successful coordination emerges from aligned self-predictions in a dynamic motor interaction”