Oh. Uhm, if we put it to the Prisonner's Dilemma language, I'd rather say -- rational people can analyze the situation and choose with whom to cooperate even if the other person is different, but stupid people need some simple and safe algorithm, such as: "cooperate with identical copies of myself, defect against everyone else".

It's not clear that someone analyzing the situation will choose to cooperate - plenty of smart people have argued that the rational behavior in prisoner's dilemma is to defect.

And I would argue that even for smart people, a simple algorithm is more likely to get everyone on board; a complicated but "better" solution which no one else follows (and that would only count as "better" if everybody was following it) is not worth following.