Toward Understanding Free-Flowing Manual Object Contact: Real-Time Interaction Between Body Position and Object Type...

Infants manually contact objects differently depending on their body position and the physical properties of objects. Previous studies have examined these factors separately, in structured laboratory settings, and laid the foundation for the investigation of the interaction of these elements. The current study revisits ideas from structured research in less controlled conditions by investigating how body position and the type of object shape manual contact with objects during free-flowing play. Nine-month-old infants (N = 80) participated in a semi-structured dyadic play session with their caregiver, interacting with four objects of two different kinds - two small and graspable objects; and two larger and stationary objects requiring specific actions to elicit an outcome (e.g., button pressing to make balls spin). The dyad was not constrained in terms of positioning, location on the floor, or movement around the room. We examined how the duration and frequency of infants' manual contact with objects varied based on the real-time interaction between object type and body position. The results indicate that infants contacted objects more frequently while sitting independently compared to other positions. Stationary objects were contacted more frequently but for shorter durations than graspable objects, regardless of the body position. Infants contacted graspable objects longer while sitting independently (compared to other positions), however, stationary objects were contacted with similar durations for all body positions. We found that durations of object contact depend on the interaction between object type and body position, which is more complex than what could be predicted by studies that examined these factors in isolation. These results highlight the need to study multiple interacting elements in less controlled settings.