Yes, in our paper, we identified the "nice" group versus the other group. The nice group is significantly worse off, but (see https://news.ycombinator.com/item?

Yes, in our paper, we identified the "nice" group versus the other group. The nice group is significantly worse off, but (see https://news.ycombinator.com/item?id=13509853 https://news.ycombinator.com/item?id=13509853) still better off than they would be in the world if they weren't being nice. We can tell the difference between the two types of people, because the nice people never defect first. Finally, with regard to identifying these types in general, one could use the (very large) dataset from this experiment to train a simulated agent that plays against a human, and quickly determine which type they fall into.