The commentaries have both revealed the implications of and challenged our approach. In this response, we reply to these concerns, discuss why the technical-reasoning hypothesis does not minimize the role of social-learning mechanisms – nor assume that technical-reasoning skills make individuals omniscient technically – and make suggestions for overcoming the classical opposition between the cultural versus cognitive niche hypothesis of cumulative technological culture.

Osiurak and Reynaud argue that cumulative technological culture is made possible by a “non-social cognitive structure” and they offer an account that aims “to escape from the social dimension” of human cognition. We challenge their position by arguing that human technical rationality is unintelligible outside of our species' uniquely social form of life, which is defined by shared intentionality :319–37; Tomasello 2019a, Becoming human: A theory of ontogeny. Cambridge, MA: Belknap Press).

Cooperation admits of degrees. When factory workers stage a slowdown, they do not cease to cooperate with management in the production of goods altogether, but they are not fully cooperative either. Full cooperation implies that participants in a joint action are committed to rendering appropriate contributions as needed toward their joint end so as to bring it about, consistently with the type of action and the generally agreed upon constraints within which they work, as efficiently as they can, where their (...) contributions are sensitive to information (where available) about how others are contributing in the sense that they adjust as needed their contributions in light of information about how others are contributing to ensure effective pursuit of their joint end, where this includes rendering aid to other participants if needed, insofar as they are able. Full cooperation entails those cooperating are engaged in a joint intentional action. Some prominent studies of joint intentional action focus exclusively on cases of full cooperation (notably that of Michael Bratman (2014)). But not all joint intentional action is fully cooperative. One example is the work slowdown. Another example is provided by competitive games like chess and football, or sports like boxing and wrestling, where participants are clearly not intending to contribute to the pursuit of all of the goals of the others engaged in the activity, even when those goals are internal to the type of activity in question, but instead intend actively to frustrate some of them. In this paper, I provide a taxonomy of forms of non-cooperative behavior within the context of behavior that is still to some degree cooperative, and I argue that the minimal conditions of joint intentional action define minimal cooperative behavior, that is, that minimally joint intentional action is per se minimally cooperative behavior. I define in precise terms what that comes to, and how it is possible in cases in which it seems that one or more participants are in one or more ways acting so as to frustrate the contributions of other participants to their joint action. (shrink)