This is largely true. I expect many don't even know what he means by "theatre of the imagination" as they don't create one or very rarely play Devil's-advocate before speaking. Runs at tve idea from the perspective of three different players. A "mind palace" or similar internal simulation takes a substantial amount of effort and practice to maintain. If you don't use it, you lose it like any high cognitive effort skill. Neuroplasticity literally melts away the structures not used.
It pays to ask yourself when making a statement "Am I a hypocrite here, am I talking about myself". Because most often, when we blame others, what we don't like in them is in us. It seems, what we hate most in others, we carry that trait which we hate in ourselves. Take bullying as an example, we may hate bullys, but possible that trait runs either in ourselves or in our family. It's difficult/confronting to see our own hypocrisy.
An IQ of 115 might correlate with a greater likelihood of generating novel thoughts, but that doesn’t mean those below that threshold are incapable of them—it’s just rarer, slower, or perhaps less easily articulated. IQ tests are timed for a reason. Given enough time, most people can solve the problems. What sets higher scorers apart is the ability to solve them quickly, hold intermediate results in mind, and build on them productively. That’s more about processing efficiency than exclusivity of thought, pencil, paper and a system allows lesser minds to contribute to leading edge thinking.
Tha aborigines in Australia never invented the wheel. One could say an aborigine has a low IQ and sure, if placed inside Wall Street they would fail. If a 'whitey' from Wall street decided to go bush in Australia unaided, they would fail and our abo mate would easily survive. IQ is relative to your environment.