Abstract
Participation in environmental movements is a social dilemma because free-riding is more beneficial for individuals.
The present study explored the reason why large-scale movements exist despite the fact that not participating is a
preferred strategy for an individual. The present study interviewed 20 core members of environmental volunteer
groups. Many of them participated in the present activity through direct communication, for example, being asked by
friends. The answers to the question "What did you get through participation?" were grouped into 4 categories:
expanding network, sense of efficacy of acting as a group, individual change/development, acquiring skills relating to
the movement. The interviewees perceived participation rewarding in many ways, and believed that their activity had
some effects. The results suggest that participation in environmental movements can be viewed as a rational action for
participants in a broad sense.
