Do you think it can be neurologically healthier to believe in the mystical and not know too much? Would you trade absolute analytical thought for not-so-deep analytical thought but better mental health? Are there any ways for an atheist to produce the neurological stability of someone with faith?
We could also try lobotomies intended to reduce one's intellect to the level of a goldfish. But I'm not sure the premise is sound, that people lacking in deep thought are necessarily happier.
For one thing, pretty much any dumb person I've ever met that had any opinions whatsoever about politics, had all their political opinions informed by belief, conspiracy theories, debunked nonsense, repeating the opinions of fear-mongering pundits, and a rejection of any kind of verifiable fact. The end result was a person who was constantly afraid of everyone else in the world, convinced that spending twice as much on the military as the next 10 countries combined wasn't going far enough, convinced that a border wall would keep bad people away, convinced that guns helped keep homicide rates down, and convinced that anyone with a different skin color, sexual preference, or voting preference was secretly a terrorist communist atheist muslim socialist who was going to take away their guns and force them into gay prostitution abortions and God would send them to hell if they didn't shout "God hates (blank)" at gay people.
An animal in the wild habitually responds to unseen threats, because the best policy when a creature has no knowledge is to assume they are constantly surrounded by threats and be ready to run or fight at all times. That ensures survival. The poor creatures are also constantly on edge, perpetually terrified of everything, and constantly imagining there might be something trying to get them around every bush and rock.
These folks who prefer faith to facts are not calm, happy, relaxed people.
I can look at the news and see all the horrible things going on in the world, and use my brain to remember other pertinent facts, like the fact that the number of people and countries engaged in violent conflicts has been going down over time, it's just that our media and technology puts what remains of those conflicts front and center so we cannot ignore them anymore. For centuries, social injustice and oppression of minorities, disbelievers, believers of a different stripe, migrants, and so forth, was all comfortably out of sight. Now we are not only addressing those issues, we put what remains front and center. In the past, someone could have gotten murdered and no one would be sure they were, because there was no way to contact them without the invention of the mobile phone, without knowing exactly where they were. In the past, nothing would be done about violent, secluded cults that raped children and forced people into marriage, underage marriage, or genital mutilation. Now, those things are in the news, widely condemned, and under constant threat of annihilation.
Knowledge is power. Knowledge fights the evils of the world. Knowledge gives me serenity and peace even when there is negative things to think about. Knowledge gives me a positive answer to a bad situation. Lack of knowledge only leads to suppression of truth, prevention of solutions, and gives the cover of a fog of ignorance to protect and shield those who would do us harm.
Faith without evidence gives people no power except willpower to believe something in defiance of a reason to do so, and in defiance of reasons not to. It gives people a ready made excuse to be stubborn. On its own, faith is neither positive nor negative. Sometimes being stubborn can be a good thing, for example, if someone stubbornly believes that if they give to charity, Jesus will reward them, that leads to charity and potentially helping others. Sometimes being stubborn can be a very negative thing.
But faith combined with a rejection of knowledge and contrary facts, evidence, or logic, is extremely dangerous.
And it doesn't make you happy. It makes you scared. It makes you imagine enemies that aren't there. It makes you feel alone in the world, surrounded by monsters. It makes you feel like you are never well-armed enough. It makes you convinced that the world is getting worse, that we are closer and closer to a violent apocalypse, and that there is no solution but to give up and hope the afterlife is a better place. It makes your every waking moment full of anxiety and fear, and anger and hatred toward those who dispute your views.
Far from being healthy, ignorance is extremely dangerous and doesn't result in the calmness you are describing. If it were the case, there wouldn't be so much xenophobia, bigotry, preference for nationalistic militaristic solutions in politics, or disconnection and social isolation from anyone who has a differing viewpoint. Those are the behaviors of highly anxious, anti-social, deeply dissatisfied people.
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