I don't still have the link, but this reminds me of a conversation I read where people were speculating that intelligent people are more likely to take strange ideas seriously and sometimes believe them, because they're good enough at telling good ideas from bad ideas that they have less need for a blanket policy against weird ideas. (Examples: transhumanism, cryptocurrency) If this holds, then intelligent people trusting others more is a specific case of intelligent people trusting their own judgement more.

Of course, conspiracy theories also fall under "strange ideas", and I don't think being a conspiracy theorist correlates with high intelligence (but I may be wrong).