In Impro, Johnstone (mentioned by jajvirta below) actual defines friendship as relationship where we can play with status more freely without retaliation, for example by joking.
He compares this to when dogs play catch, always switching pursuer and pursued roles in the middle of the play. Of course dogs can both play catch, and really pursue prey.
Or, rather, the causal relationship is reverse: action causes conscious thought (rationalization).
Once you start looking for it, you can see evidence for this in many places. Quite a few neuroscientists have adopted this view.