Cooperation may be voluntary, may be enforced. It depends on the situation. In agricultural operations different members of the group perform different activities. They grow different crops. Some focus on fishing or growing vegetables and some perform supportive activities.
For example, preparing tools and equipment. They all cooperate each other to get good harvest. This is voluntary cooperation, which is intrinsic in nature.
But the factory workers do cooperate with the owners in performing their tasks because total production depends on their mutual relations but it is actually system requirement. This cooperation is a prerequisite for job sustenance. Behind the cooperation there are many norms. So this is enforced cooperation which is extrinsic. The feeling of fulfillment and creativity of a weaver or potter or ironsmith is voluntary cooperation.
In contrast, a worker involved in a factory whose sole task may be to pull lever or press a button throughout the day. Cooperation in such a situation would be enforced.