Self interest in collective action

Collective action is seen everywhere, from the cities to the villages. For my fieldwork, I went to Kanjani village in Nandurbar district in Maharashtra. The village is a tribal village and kinship prevails there. The sense of bonding and co-operation that was present there was the first time I saw services being provided by various villagers to others at no cost. For eg. An ironsmith in the village would make shears and knives and would not charge any money and neither would he accept anything in kind. At that time, I did not realise the importance of such acts, but after a few sessions of CAC, I realised that if the ironsmith is providing his services free of cost, then he expects an equal amount of service in return. This form of give and take is a result of the self interest of a person, but it is essential to the overall co-operative spirit of the village.
This kind of self interest (or selfishness), results not from a feeling of egotism or self – centeredness, but comes from the basic need of survival. Even an individual ant or bee, which portrays a great show of co-operative action in its swarm or hive, performs the action for its own food and survival needs. So, I think it is correct if we say that co-operation without self interest does not exist. It is only at the highest level of co-operation, that the group begins to think about members outside its group, that such a thing is possible. But such cases are rare.
Another reason for collective action can be the herd mentality. A lot of times, especially during the rebellious teen years, people become part of a group in spite of trying to. A good example of such a situation can be when people become part of a fighting group. Generally, it is just one or two individuals who have some motive behind getting into an argument or a fight. But many among the fighting members are there just because they are aligned to the one or two who actually started the fight.