Fascinating, thanks. I already knew a lot of this in a vague manner, but it was nice to see it made concrete and clear.

This seems to have obvious evpsych implications regarding emotions such as love and friendship - if you love somebody enough that you can't take serious actions against them, even if it would otherwise be rational (for a purely selfish agent), then it's also more profitable for your partner to keep interacting with you. Of course, handicapping yourself is only a good idea if the other person isn't out to ruthlessly exploit you anyway, so love often demands a lot of reciprocity - unless, perhaps (getting into strong armchair evpsych territory here), the status difference is so large that you have potentially more to gain than lose anyway. I expect somebody here can give a pointer to the standard papers about this?