  We propose a decision-making model for joint intentionality by interpreting
it as group-mindedness at the microlevel. We apply this model to give a formal
justification of the first part of the Interdependence Hypothesis due to
Tomasello et al. [Current Anthropology, 2012] which asserts that the emergence
of joint intentionality evolved due to the challenges of difficult
collaborative foraging practices among early humans, and that its evolution led
to robust collaboration and some form of altruism.
  In another application of the microlevel group-mindedness we consider the
problem of establishing cooperation in high-risk-of-defection strategic
conflicts and we show that the emergence of cooperation in such situations can
be explained in the context of cultural group selection as the result of
adaptive learning.
