The evolutionary justification for this is, of course the following: if evolution were a designer, trying to ensure that thinking beings learned and knew what they had to to survive, a cheaper rule than putting everything into the head from the start is “learn from those around you, because they are not dead”. The term Grayling uses, which I have linked, espalier is entirely appropriate: we train young minds to catch the (environmental) “light”. This includes fire and tigers (in Africa? really?), but it also includes believers in tribal gods. So it is entirely rational to believe what you are told by non-dead elders, since if they can get to that age without losing the battle in the struggle for life, then you ought to as well, if the conditions haven’t yet been changed.
Therein lies the rub. Until fairly recently, traditions changed pretty slowly. it was a very good bet that if you emulated your parents and peers, then their “Good Tricks” for living (including living amongst other people) would work equally well for you. A heuristic that says “do what the majority do” is going to balance the costs of early adoption with those of late adoption, and ensure that your cognitive task for getting up to cultural speed is as low as it can be. So it is adaptive to believe what all around you believe, most of the time.
Along came printing and other mass communication methods. Now the environs are changing fairly rapidly, as Papuans and Amazon indians and San Bushmen all are exposed to the latest vapidity from Hollywood or Paris or Redmond. So learning what your elders know is less useful (although it is often overstated how much different it really is. I could carry on a good conversation with my parents’ generation in the 1940s, I think). The differential rate of change of traditions is now much greater than before.
I focus a lot on these same issues but in the context of the broader ethics of traditionalism. One of the things that studying Nietzsche extensively has made me cognizant of is how much moralities in their essence and their history require deference to tradition for tradition’s sake. Contemporary moral philosophy is (rightly) concerned with finding justifications for morality and part of that task is to formulate conceptions of morality which are highly justifiable. But there is an irrationalistic, traditionalistic streak to morality because it’s part of an adaptation to group think so as to benefit from the herd’s accumulated wisdom.
Rather than evolving minds that would be first inclined to independently reassess traditions for ourselves and quickly improve them, it worked better to keep us on the same page, deferring instinctually (in what Nietzsche calls the “herd instinct”) to the most tested and reliable traditions, at the expense of better alternatives because the risk of disaster from failed experiments was too great. This means that learning about how to improve our ways of life has always been a glacially slow process, inherently biased towards received interpretations of the world.
So the struggle to get people to think outside of received ways of thinking in intellectual matters is just a subset of the conformist, traditionalistic prejudice of the mind in general and is bound up with the same impulses that keep us morally bound to a community. Our process of developing our abstract accounts of the world is psychologically more about aligning our perceptions with the conceptions of the world that our culture gives us (partially even just through the language it gives us, loaded with assumptions as that itself is).
This is why the task of persuading people is much harder than just presenting them with good arguments. New paradigms developed on abstract levels with scientific or moral rigorousness need to be relentlessly filtered into the mainstream so that they can become part of the collective group think before most people will ever even be able to countenance the ideas in them or seriously consider them.