What do you suppose compels social animals to cooperate socially? I can imagine a few possibilities:
1. Maximizing self interest using an understanding of social contract theory
2. A complex system of instincts that depends on others behavior, but doesn't manifest as intuition about the reasons for those behaviors
3. Like 2, but it manifests as an intuitive undestanding of how others may feel
I admit, 1 seems unlikely, even for humans. 2 and 3 sound more plausible, but 3 seems like the simpler explanation to me. We have an example case of it in humans (of course humans may additionally reason about others intent), and I'd expect similar tendencies to have similar mechanisms. Plus, grouping behaviors into intents reduces the number of rules needed for the observed behavior -> response mapping at the cost of some pattern recognition ability.
It's possible there's another explanation, including why similar tendencies aren't explained by similar mechanisms, despite the availability of similar "hardware". If there is, I'm not clever enough to have thought of it.
