Not all that long ago the very same thing could be said about a wide variety of things that we now take for granted/baseline, like basic competency in reading, writing, and arithmetic as one example. Unlike those things, thinking to a certain degree of competency is innate in human beings, but exceptionally skillful thinking in things like logic and epistemology must be learned...but for people to learn them, they must be taught. As it is, numerous errors can be easily found even in intellectual spaces online, demonstrating that even the cream of the crop is far from perfect....and as for the less intellectual places (the overwhelming majority), well we're all familiar with how bad those are.
> Not all that long ago the very same thing could be said about a wide variety of things that we now take for granted/baseline, like basic competency in reading, writing, and arithmetic as one example. Unlike those things, thinking to a certain degree of competency is innate in human beings
You seem to be conflating openness to persuasion as a component of personality, and openness as a learnable mental skill.
It isn't inconsistent to assert that being open to persuasion is in fact both.
Most people I encounter find (heuristically) this belief/philosophy to be "wrong"/bizarre if not downright offensive, but I sincerely believe that this type of thinking (a bias towards conclusiveness and away from epistemic soundness and curiosity, and this is but one example among many) is one of the biggest root cause problems of problems on this planet. A prime example of where this is causing serious (life and death) problems is with vaccine hesitancy - people love to hate on anti-vaxxers, asserting that they "are" "stupid", but rarely have I encountered a "smart" critic who has the cognitive ability (openness) to even consider the possibility that their perception of the situation is incorrect (if not downright harmful from a causality perspective).
A (likely offensive, as a demonstration of my point) way to think about my stance/conceptualization that might help communicate my frustration: I feel as frustrated with pro-vaxxers (or, ~neurotypical ~Western human beings in general) as pro-vaxxers feel with anti-vaxxers...and ironically (or not), it seems at least as difficult to reason with them (which I believe well demonstrates the ubiquitous nature of the phenomenon).
Which studies?
This sounds like one of those new-agey empathic business tutorials which are actually hidden racism, classism and eugenicism 101s.
There are ways to "picking the lock" however, as another part. That's the basis of marketing and sales. The processes are very well defined though the results are stochastic rather than deterministic. Hence marketing and sales are "number games".
But such techniques are merely tools without specific morality or ethics - never give the human a free pass on morality or ethics because only humans can make such decisions.