Actors change their movement strategies to complement a coactor's movements when performing cooperative tasks. To further investigate this topic, the authors designed a pegboard task whereby a participant-confederate pair worked together to move a peg from one side of the board to the other. The authors examined how the experience of working with a helpful confederate versus less helpful confederate influenced the participant's movement behavior. Results provide evidence that participants change their movement behaviors in response to the actions of the confederate. Here the human capacity to act in such a manner exemplifies an individual's ability to utilize his or her own action system to understand others and interact to complete joint action tasks. Individuals appear to adapt their behavior to their experiences, and thus may be helpful in some contexts and less helpful in others.
Keywords: complementary action; imitation; joint action; movement behavior.