As this post notes, the human learning process (somewhat) consistently converges to niceness. Evolution might have had some weird, inhuman reason for configuring a learning process to converge to niceness, but it still built such a learning process.
It therefore seems very worthwhile to understand what part of the human learning process allows for niceness to emerge in humans.
Skyrms makes the case for similar explanations at these two levels of description. Evolutionary dynamics and within-lifetime dynamics might be very different, but the explanation for how they can lead to cooperative outcomes is similar.
His argument is that within-lifetime, however complex human’s learning process may be, it has the critical feature of imitating success. (This is very different from standard game theory’s CDT-like reasoning-from-first-principles about what would cause success.) This, combined with the same “geographical correlation” and “frequent iterated interaction” arguments that were relevant to the evolutionary story, predicts that cooperative strategies will spread.
(On the border between a more-cooperative cluster of people and a less-cooperative cluster, people in the middle will see that cooperation leads to success.)
I note that none of these is obviously the same as the explanation Skyrms gives.
Skyrms is considering broader reasons for correlation of strategies than kinship alone; in particular, the idea that humans copy success when they see it is critical for his story.
Reciprocal altruism feels like a description rather than an explanation. How does reciprocal altruism get started?
Group selection is again, just one way in which strategies can become correlated.