While Michael Tomasello cannot give an ultimate answer to the question on why we cooperate his book is an interesting contribution to the ongoing discussion. And thus his book’s form is also more styled as an discussion. In the first part he presents his own research on primates and young human children and his own conclusions. In the second part some additional prominent scientists from the fields of developmental psychology, anthropology, and philosophy are allowed to respond with their opposing views on his interpretations based on their own research.
It is clear that the different authors do not agree on the details but there seems to be some overlap. All in all it is a nice cooperative effort. By allowing opposing views to be voiced the whole endeavor becomes more balanced and the reader gains a more comprehensive picture of the research on human cooperative behavior.
Though I was already more or less aware of the various approaches there was something I did not consciously know so far. Tomasello distinguishes three domains of altruism: goods, services, and information that translate to the actions sharing, helping, and informing. As Tomasello points out, these domains entail different costs and benefits. Therefore I am inclined to adopt this categorization for my own research.