Here is an interesting excerpt:
Others say we have no special device for representing numbers in the brain and that far from being an independent ability or instinct, our number sense flows from general intelligence and reasoning, or spatial awareness, or linguistic abilities - or some combination of all three. So why is Butterworth convinced this is wrong?
Meeting and studying people who lacked the normal version of the sense was a big factor, he says -
He should meet many of those hardcases that remain out of the MMT paradigm then.
Those who remain out of the MMT paradigm after being introduced to MMT, I believe suffer from some form of a Mathematical Cognition deficiency. The interview at the link above with Butterworth talks about some extreme forms of deficiency, and I do not believe that those that remain adverse to MMT possess such extreme deficiencies. But their cognitive deficiencies are perhaps still very important to recognize as many of these people occupy high level policy making positions.
This subject accounts for much of the non-acceptance of MMT throughout economic orthodoxy imo.