I agree with what you are saying, Atheos. The result of religious thinking leads to a lack of intelligence, not that a lack of intelligence leads to religious thinking.
I gotta rant here, but not specifically at you, Malintent, but the whole conversation.
I think it's both. I don't think you can separate the impingement of external ideological culture from the operation of individual minds within the culture. It's a two-way street, or more accurately, a mulitple way street.
Two important facts about human brains that I find useful to remember, plasticity and energy conservation, explain a lot about belief and behavior. There's much more, of course, but these neurological realities go a long way in shaping our lives and entire cultures. They're the drivers behind our "echo chamber" tendencies. We seek out confirmation because it's more comfortable than the stuff that challenges our beliefs, and we allow the resulting echo chamber to further strengthen our beliefs because that, too, is more comfortable than venturing out into the unfamiliar.
Religious ideology that eschews questioning and rewards wishful thinking and other cognitive pitfalls only strengthens the neural pathways that support such thinking and weakens other intellectual functions such as creativity.
An ideology or culture that encourages questioning strengthens different pathways and functions such as openness and curiosity unfettered by fear of punishment, and that alone impacts overall perception as well as specific aspects of intelligence, one being the ability to consider many possibilities in problem solving. (In some ideological groups, just learning about how one's brain works is itself a sin!)
On the other hand, most cognitive pitfalls that affect our views and choices are just lazy ways of thinking, which doesn't mean the
person is lazy, but rather our lazy, energy-hog brains, which don't like spending resources to change those pathways of thinking that do not threaten survival and well being (including the sense of well being of the self image).
Within an ideological group where everyone pretty much agrees on certain beliefs and assumptions, no one cares if the assumptions are wrong if they're not challenged by discomfort in day to day life or by events that bring dissonance enough for the brain to rework its pathways for relief. And often that relief is sought by rewiring in the direction of digging in rather than exploration because it's less socially risky.
This is why, when religious tenets demonize aspects of our marvelous humanness, those individuals with those unauthorized traits or behaviors suffer, some for their whole lives and others up until their brains give up the glucose and they begin actively seeking a more humane worldview.
At the risk of conflating the issue, I'd add that compartmentalization plays a huge role in belief. We see this in scientists with supernatural beliefs as well as devout religionists who are also wicked sharp in cognitive ability in other areas.
Furthermore, some belief systems are called religions but are more accurately called philosophies, such as some forms of Buddhism wherein questioning and self reflection are valued over dogma.
I'm not a Buddhist, but I respect the hell out of the Dali Lama when he says “If scientific analysis were conclusively to demonstrate certain claims in Buddhism to be false, then we must accept the findings of science and abandon those claims.”
And you are absolutely right that it comes down to who you trust for knowledge...
That's social influence in a nutshell, yes. Very powerful, no matter who you are or how enlightened or smart or aware or independent you think you are.
or even understanding what it is to have knowledge ('just knowing', versus 'learning').
This line of philosophizing requires spending some glucose, and within religious ideologies, it's hit or miss whether someone uses such intellectual pondering to find their way to more realistic means of determining truth or if they just use it to devise more clever mental tap dancing to defend the indefensible.
So if your belief system, at its core, values questioning and willingness toange beliefs, your brain is built to go along with that and as a result, you have a massive intellectual advantage over those who spend their lives within an ideological collective that says change and doubt are sins punishable by eternal torture.
Religion is dumb and makes us dumber. Critical thinking means questioning and being open to possibilities. It's the anti-religion, not because it's just another, opposing belief system, but because critical thinking threatens the cognitive functions that give rise to religious belief at its root as well as drive further propogation.
End rant. If you read this far, I thank you.
