Conclusion

Abstract

There are laboratory and field experiments for approaches to joint action. We have to study interpersonal information-processing in joint action according to the merits and demerits in field and laboratory experiments. Emergent and planned coordination is separately studied so far. But human actions are not clearly divided by emergent and planned coordination. Thus, it may be necessary to recognize hybrid forms of coordination which are part emergent, part planned. In future studies, we will examine three experiments as follows: first, pairs of participants make complementary and synchronous force production exclusively when the target force shared by the participants and the total force produced by them are presented visually. This innovative finding suggests that two participants represent the target force shared by them in their brain. Thus, we have to find a behavioral indicator as the representation of the action target shared by two participants. Second, focusing a target of our study to a task of force production, we have to examine effects of different combinations of types of force production (continuous, periodic, or discrete force production) and target force (relative or absolute value) on the two-heads-better-than-one effect. Third, we have to examine a hypothesis (social loafing) that an increase in the number of participants in joint action resulted in a decrease in individual contribution.