If you call this success, you set a pretty low bar. If by success you mean survival, then when we are around as long as sharks, alligators, and crocodiles, then we have something to talk about.

As a younger man I used to use radio waves and how they penetrate everything invisibly as my evidence for a gateway into the supernatural. All that did was open the imagination of nonsense and today I no longer believe anything supernatural.
A lot of what the hunter-gatherers are doing is symbolic and a carry over of thousands of years. Most of them know this. They kill the noble beast for food and it's hide, paying homage to the creature because we are all in a "supply and demand" of nature itself. This is valid from the smallest to the greatest of all of us.

I think, by "realist", you mean "a practical person".

Yes, it is possible to be completely practical in your everyday life, while still believing that there is a big spirit in the sky running everything. Billions of people do it. But in the larger sense, you're still not a realist. A realist copes with the lack of a cosmic plan, the fact that there's no Apocalypse coming, the fact that we are not the center of the universe except in our imagination. A realist deals with real life.

No it's not possible. Hunter-gatherers don't know the reasons for what happens in their world, which is why they invent gods/spirits of the gaps.. And as far as the modern day world is concerned, their cultures have more or less gone extinct.

It's called compartmentalization. Many people think scientifically about some things, but superstitiously about other things. Scientists who go to church do not exercise the scientific method on Sunday mornings. If they did, they would not be going to church at all. They would disprove the superstitious claims of the church, and dismiss religion as a scam (to control people and get their donations).

I think there is a book about this archealogist's research on how a lot of the songs and myths of ancient people are really encoded memory palaces. There is no doubt that being a hunter/gatherer is tough... You have to have encyclopedic knowledge of the flora and fauna in your region to be effective at hunting and so you don't pick plants that will poison the tribe. So, she proposes that all of this information is encoded in songs and myths because it's easier to remember this information like that.

What did I just read? Okay. I know. You're just pulling our chain, right? Looking for reactions, right? Wanting to see how people respond to bullshit? Well, I won't give you the satisfaction by reacting to your nonsensical posits.

Waiter..! Waiter..! Check please.

No just defective

Horseshit.
What a complete load of justification.

Excellent post! and just as meaningful today as it was throughout human evolution.

Niels Bohr:

I myself find the division of the world into an objective and a subjective side much too arbitrary. The fact that religions through the ages have spoken in images, parables, and paradoxes means simply that there are no other ways of grasping the reality to which they refer. But that does not mean that it is not a genuine reality. And splitting this reality into an objective and a subjective side won't get us very far.

Well that gave me a chuckle

Well that gave me a chuckle

Their beliefs in "a host of supernatural agents and entities" makes them by definition NOT 100% realists.
Instead they have a culture which attempts to explain what they do not understand by this means.
" If their beliefs in spirits or magic interfered negatively with their knowledge of the world around them, they would have died long ago, their cultures would have gone extinct."
Most have.
Others were contaminated by western culture. As soon as they saw the technological advancements it became impossible not to accept that the westerners had discovered something, they had Iron, steel tools, and so forth.
They ALSO had Gods, just different ones, which explain away the issues for which humans either lack answers or for which they find the answers so distasteful they prefer an assertion without evidence which they find more pleasant to an unpleasant and likely reality we cannot prove.

I do not see this as a dual life, but compartmentalized life. When it comes to your practical life, science is fine, put gas in your truck, bring the laundry in when it is dry.
When it comes to conceptual reality the notion of NO ABSOLUTE ANSWER scares the hell out of some folks. What happens when we die? (You dead) Is there an absolute justice? (no) these answers are unpalatable to many and they just prefer to think THEY are not responsible for making the world AS JUST AS POSSIBLE, instead they pawn it off on a God of some kind and remain cultural children "Its not OUR fault, Its God's mysterious will". To abandon this ideology is to assume a burden not a one of us can bear, and which we all have to strive to bear as one.

Some folks cannot face that, in the same way that some folks can't face test day, or big game day, or any other trial of life but magnified.

When you grow up in the cave you watch the shadows on the wall like everyone else. It takes both a curious mind and a determination of personality to turn around and see the entrance to that cave.

PS The Piraha people live in the Amazon and NEVER created any Gods for themselves.
Read "Don't sleep there are Snakes" The traditional "good night" greeting of the Piraha

So how do you explain my being a realist and NOT believing in supernatural agents and entities ?

Is contradictory when you start to spend resources in rituals and people that are has no function for society.