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Development of role-differentiated bimanual manipulation during the infant's first year
Marliese Kimmerle1, Claudio L Ferre, Kathleen A Kotwica
1Department of Kinesiology Windsor University Windsor, Ontario, Canada.
Insights
Role-differentiated bimanual manipulation (RDBM) emerges early in infants but only becomes a skill by 13 months. Toy complexity influences RDBM development and intentionality, offering insights into infant sensorimotor skills.
Area of Science:
- Developmental Psychology
- Infant Motor Skills
- Bimanual Coordination
Background:
- Role-differentiated bimanual manipulation (RDBM) involves distinct hand actions, observed in infants from 7 months.
- RDBM development into a skill requires appropriate frequency, duration, and intentionality in task execution.
Purpose of the Study:
- To longitudinally assess the emergence and development of RDBM as a skill in infants.
- To examine the influence of toy complexity on RDBM types, frequency, duration, and intentionality.
- To establish criteria for defining infant sensorimotor skills.
Main Methods:
- Longitudinal study of 24 infants at 7, 9, 11, and 13 months.
- Observation of RDBM types, frequency, and duration using single-part and two-part toys.
- Analysis of action sequences for evidence of intentionality.
Main Results:
- While RDBM types appear early, skill characteristics emerge by 13 months.
- Toy complexity significantly impacts RDBM elicitation, behavior type, and action organization.
- Infants demonstrate increasing intentionality in RDBM with development.
Conclusions:
- RDBM transitions from a basic movement to a skilled behavior between 7 and 13 months.
- Toy properties are critical factors modulating infant RDBM development.
- This study provides criteria for defining infant sensorimotor skills.
Abstract:
Role-differentiated bimanual manipulation (RDBM) is a complementary movement of both hands that requires differentiation between actions of the hands. Previous research showed that RDBM can be observed in infants as early as 7 months. However, RDBM could be considered a skill only when its frequency, duration, and use is appropriate for the type of manual task, and there is some evidence of intentionality in use. Twenty-four normally developing infants were studied longitudinally at 7, 9, 11, and 13 months to assess the frequency and duration of five clearly different types of RDBM with three "single-part" and three "two-part" toys as they emerge during development. Also, the sequences of actions that lead to RDBM were examined for evidence of "intentionality." The results show that although the each type of RDBM appears early in infancy, RDBM only begins to exhibit the characters of a skill by 13 months. Moreover, the type of toy influences not only the likelihood of eliciting role differentiation, but also the type of RDBM behavior and the organization of the sequence of actions that lead to RDBM. Some useful criteria for defining an infant sensorimotor skill are provided in discussion.
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