I believe this is true.
Intelligence, even great intellect, does not make one proof against illusion.
There is a lot of evidence around that indicates that Ronald Reagan was extremely smart and in controll of the Whitehouse, but if you treasure the illusion of Reagan the dummy and Bush the sock puppet you can see the ventriloquist moveing his lips , when he isn't even there.
Being smarter can mean that you are only more skilled at fooling yourself.
Lets not be smug , I am saying that we can all be fooled.