You right, I did not catch your use of the word assertion. English is not my first language. I also must say that I do not completely agree with the original post. There is a difference between believing your thoughts can get you what you want and that your thought can hinder you from getting what you want. Despite this, I do believe the assertion Anil Seth makes in his TED talk is not limited to "us molding our (and other's) psychology". It extends to claim that reality is an illusion created by our brains and therefore a hallucination. Reality as we understand it is our perception and our brain therefore literally molds it. This I find is, despite not a particularly new claim, a pretty monumental assertion! If it's true, on the scale of monumentality its right up there next to the Copernicus revolution in terms of how we define our relationship to nature and the universe.