"The experiment seems poorly designed if the purpose is to simulate the real world"
The stated purpose is to try to reproduce the same experiments and behaviors that observed in other primates.
Some insights I get:
1. In those conditions, our behavior is very similar to other primates.
2. The splitting phase is not influenced by the collaboration phase (I can't avoid to note that you don't choose to apply this insight to start ups).
3. There is some component that we don't understand that account for the difference with the Nash equilibrium.
4. When you have a hammer everything looks like a nail