Rich countries are less religious than poorer countries, as discovered by Pew Research Center. The two big outliers are the U.S. and China. Americans are far more religious than expected: on par with Lebanon despite 4 times its average income. China is an extreme outlier in the other direction. In the middle are the Nordics: liberal capitalist democracies where 75%+ are atheist, agnostic or unaffiliated. Though tolerance is practised, culturally these irreligious regions are religious monopolies, with nationally enforced primary religions, enforced initially by past royalty and continuing out of habit and inertia.
Whenever doctrine clashes with economics, religions must adapt, or their followers incur a penalty, which can really shake their beliefs. When a religion is in a monopolistic position and dominates a community, the only acceptable alternative is apathy. You either believe or you don’t: there is no other viable option. If a religious institution in this situation gets lazy and makes mistakes (and they always do), they drive the people with the weakest devotion to further lapse. When old habits are broken, they tend to stay that way. Most adopt their religion as children, and with less intensely religious parents, children are shown to be far less likely to be religious when they grow up.
Strict cultural norms relax as the defectors begin to outnumber the fanatics. Just like monopoly companies, monopolistic religious institutions fail to innovate and eventually decline in relevance, bringing the whole category down with them as people’s attention diverts to other things. This increasingly creates an opening for secular humanists wielding evidence-based policies. Wealth creation is unleashed, generating the tax base necessary for social welfare spending, further decreasing reliance on the church. The social safety net provided by the state diminishes the incentive to stay in unhappy marriages, cutting off spouse-to-spouse transmission as well.
Communism was a grand experiment that attempted to shortcut this shift, hoping a technocratic elite unencumbered by ‘irrational’ religious beliefs would bring untold wealth. Of course it never worked out the way they imagined. Banning religion is just a monopoly of another kind. Ideology doesn’t need to be rooted in the supernatural to be toxic. Lack of religiosity didn’t stop the Soviets from exhibiting bad beliefs. Good beliefs were crowded out by Communist propaganda, and anyone who threatened the official narrative was summarily executed or sent to the gulag.
In the U.S. a different experiment was underfoot. Culturally Americans have always believed that the remedy to speech you don’t like is "more speech, not enforced silence”, as Justice Brandeis put it. The U.S. never lost its religiosity, and became a became a free market of ideas. Freedoms of religion, assembly and speech are enshrined in law, and culturally a critical mass of its citizens inherited the beliefs of the founding fathers around tolerance and religious freedom. As a result, more than 50% of Americans change religious affiliation in their lifetimes. Faith faces economic reality without protection from the state, which means it faces selection pressure. If you don’t like your religion you’re free to get a new one. In America religions literally evolve, and its survival of the fittest. Those that survive come out the process stronger than they would have been inhabiting a cozy niche, protected by some european monarch. All this comes at a cost to the unaffiliated, because when you have more competent religions, there’s less role for the state to play: explaining America’s relatively under-developed social welfare infrastructure.
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