This is a good point. To the extent that social competency is zero-sum, we want to learn an exclusive, secret art (I am sure it is not, taken as a whole, for the same reason that trade and cooperation aren't only zero-sum, but individual skills as actually employed may be).

The desire for powerful secrets biases us - for example, toward accepting nonsense from a cult leader. I'd rather instead include all the available similarly-minded smart people (who may occasional offer fresh insights), even though they would also be my most effective competition.