Interesting. Can I ask you to unpack this statement? I'm curious what exactly you're comparing.

The difference between "has practiced a movement to mastery" and "has never performed a movement before" can be very large, like my powerlifter/snatch example in the other comment. But this is comparing zero practice to a very large amount of practice over a very long period of time. I would find it easy to believe that IQ tests see much greater returns from small amounts of practice.