Tacit knowledge can develop in a number of ways. It can develop consciously or subconsciously. Perceptual learning (a la Reber), is a mode of learning that's based on repetition. Sometimes of an explicit message, often not.
Tacit knowledge cannot be an explicit message though, as that makes it explicit knowledge.
That the attitude 'I dislike non-Muslims' is held subconsciously doesn't make it tacit knowledge, it makes it latent explicit knowledge. A latent attitude can easily be crystalised into explicit knowledge if activated by a message/event.
Perceptual learning is not simply all learning via repetition (a la rote learning), but a special type of learning that fundamentally alters your sensory reaction to some part of the environment.
The gaining of a latent attitude via exposure would be represented by a), whereas perceptual learning relates to b).
a) A tendency to become favourable to messages we are repeatedly exposed to
b) A fundamental change in cognition caused by repeated exposure to a certain type of environmental stimulus that can only be undone by prolonged exposure to an alternative environmental stimulus..
I'm most familiar with PL used in situations in which the learner has an explicit intention to learn. It's often used to convey tacit knowledge (unspeakable) from a master to a beginner. For example, in WW II there were folks in England who could hear planes in the distance and "know" whether they were friendly planes or enemy planes. In order to spread this useful skill to others, a highly repetitive PL approach was used. I guess I would say it's more commonly about learning an assessment skill rather than developing a preference. But I think it could go either way.
This would be an example for tacit knowledge, but it differs from the Quran example, which regards latent preference/prejudice regarding a group.
As regards perceptual learning in this case you can't simply flip a switch and respond differently to the sound of the planes; you still associate them with friendly/enemy. To change this assumption you would need repeated exposure to engine sounds that caused a reevaluation over time (perhaps if a new kind of planes was introduced for example).
With latent preference you can, in theory, simply flip a switch and view the group differently. I'm sure you can think of an example where you have had a sudden about face regarding a person/idea/issue that you were hostile to based on a single instance that made you question you initial viewpoint.
I also don't think you can inoculate yourself against perceptual learning, whereas you can regarding a message of preference (no amount of Trump soundbites will turn an ardent Trump hater on their own).
You don't need to evaluate each individual example, just apply a general heuristic that negates the need to consider the individual instances (Trump is a lying, incompetent **** for example).
Yes, we're largely agreed on the power of intention. But I wouldn't say it's black and white. Even someone who hates trump might - over time - begin to harbor a concern over "caravans of invaders".
This would relate to traditional attitude change rather than perceptual learning . Exposure to message makes you question initial assumption and upon further investigation/consideration you revise an opinion. It requires a willingness to question an initial belief rather than mere exposure and relates to an attitude rather than an aspect of sense perception.
Which is closer to your opinion? Maybe I'm wrong, but I think you really believe closer to a) but are couching it in the language of b) (which I believe is not an accurate use of the terminology).
a) Exposure to consistent negative messages regarding a group, on average, increases the likelihood you will hold negative attitudes towards them although there are many other factors that influence this issue, particularly your preexisting beliefs.
b) Simple exposure to a repeated message creates a perceptual learning environment which (almost)
necessitates the subconscious semi-permanent internalisation of the attitude expressed in the message given sufficient exposure.
In the case of scripture, indoctrination is a very common strategy used on children. In the case of children, they won't have much of an intention going in. They are easier to indoctrinate.
I'd say that is far less about the scripture itself though, and far more to do with what the adult tells them is true regarding the scripture. Almost any kid who gets exposed to any religious text will only do so after being told the main 'truths' of the religion anyway.
I'd say that, in general, the scripture itself doesn't play a massive role as it is not learned in a vacuum and is not their primary source of religious attitudes.