Article at http://www.businessinsider.com/prisoners-dilemma-in-real-life-2013-7#ixzz2ZxwzT6nj, seems revelant to a lot of the discussion here.
There've been studies about people who consider themselves to be relatively successful are less cooperative than people who consider themselves relatively unsuccessful. The study referenced in that article seems to bear this out.
So if you want the other party to cooperate, should you attempt to give that party the impression it has been relatively unsuccessful, at least if that party is human?
Thanks for that explanation. The complexity factor hadn't occurred to me.