Kicking Away the Ladder?

A report from the Pew Center is the latest to document America’s rapidly declining religiosity. Pew’s numbers show a 12-point decrease in the percentage of Americans calling themselves Christians between 2009 and 2019, while those describing themselves as atheists, agnostics, or “nothing in particular” have risen from 17% to 26%.

These findings are mirrored in the General Social Survey, which has been asking respondents about their religious affiliation since 1972.

religious nones
Shaded area represents 95% confidence interval

The demographic surge of the religiously unaffiliated is a story of treatment effects triumphing over selection effects. A little context will help explain.

Natural selection seems to decidedly favor the religious. As the social psychologist Ara Norenzayan details in Big Gods (an excellent if at times slow book), religious societies, specifically those that follow omnipotent, moralizing “Big Gods,” have historically been able to outcompete others. To summarize Norenzayan’s findings, this is due to three factors, the first two of which are increased trust and greater social stability, both made possible by supernatural monitors (gods) that have allowed societies to scale by “building moral communities of strangers.”

In recent history, some societies (think Scandinavia and Japan) have been able to “kick away the ladder” of religion, replicating the monitoring effects of Big Gods through trusted civic institutions—police, courts, and others that allow for anonymous actors to cooperate in the same way religion used to. But there’s one other important advantage of religious societies that secular societies haven‘t been able to engineer: above-replacement fertility rates.

Fertility by Religion
I’ve restricted my search to 30 – 45-year-olds to try to account for the fact that older Americans are on average more religious and have more children.

The religiously unaffiliated reproduce at notably lower rates—so much so that, even as I’m writing a blog post about their astronomical demographic growth in America, the Pew Center projects they will decline as a share of the global population, from 16% to 13% between 2010 and 2050.

shrinking religiously unaffiliated.png

Followers of Big Gods, especially those of fundamentalist branches of religion, tend to have more children. Note: this is mirrored by the liberal-conservative fertility gap, and both are fueled in part by divergent views on reproduction.

To give you a sloppy illustration, consider the graph below, which I constructed using national-level data from 55 countries that appear in the 2012 Win-Gallup International Global Index of Religiosity and Atheism and Gapminder total fertility rate data from the same year. Nearly every country with an above-replacement fertility rate has a majority-religious population by quite a large margin.

more religion more babies
Horizontal line represents “replacement rate” of 2.1 children per woman. Vertical line represents median religious society in the data set.

In a personal email quoted by Norenzayan in Big Gods, a colleague confides that despite reviewing all available data and case studies back to early Greece and India, he was unable to find a single example of a secular society maintaining a birth rate higher than two children per women for even a century. France, Germany, Japan, and quite a few other countries are trying—and failing—to address this problem with a variety of subsidies. Thus far, there is no secular substitute for religion’s fertility premium.

So with forces of nature solidly in support of religion, why is it rapidly losing ground across the rich world? It turns out there are countervailing secularizing forces that, it feels safe to say, have grown powerful enough to chip away at the natural demographic advantage of the religious. Unlike the selection effects that propel religiosity, these are treatment effects, meaning they’re driven by exposure to certain conditions. In addition to the aforementioned creation of secular civic institutions, those conditions include education, rising incomes, and the general removal of existential threat (of the “where is my food coming from” variety, anyway).

Notably, somewhere around 78% of all “religious nones” are “converts,” if you will, meaning they were born into a religion and ceased to identify with it over time.

While there is some observable increase of religious unaffiliation within generations, the flight from religiosity is largely driven by generational replacement. In other words, it’s not like longtime worshipers have suddenly lost faith en masse—it’s that their grandchildren aren’t interested, and older generations are losing ground demographically. This fits the pattern of other paradigmatic shifts in public opinion, and to me, suggests there’s an element of timing involved, that conditional secularization may be contingent upon one’s formative environment.

The question that remains to be seen is whether or not the secularizing rich world can support itself. Our economies, infrastructure, and social welfare systems are reliant on people, and a large population that doesn’t reproduce will age with dramatic consequences (see Baby Boomers). In the long run, this is probably one of the most consequential political issues out there.

Science and Politics: An Abusive Relationship

Decades before Luis Pasteur fostered scientific consensus on germ theory, Ignaz Semmelweis was imploring obstetricians to wash their hands after handling corpses. His work did little to inspire his fellow medical practitioners. On the contrary, he was met with indignation and disbelief at almost every turn. Though aided by his increasingly erratic behavior and political inelegance, there is no doubt that his alienation from the medical community was due in part to his then-heretical proposals.

We’ve come a long way since the Roman Inquisition locked Galileo under house arrest for advancing the theory of heliocentricity. Yet still, skepticism is a trait that can inspire zealous culture warriors to brand others “deniers” or deride them as being “anti-science.”

Of course, there’s nothing more scientific than scrutinizing an accepted norm. The scientific process is dependent on constant refinement by people attempting to prove each other wrong. Indeed, science needs skepticism to sharpen its ham-fisted hypotheses into acute theories.

Our devotion to explaining the universe through rational observation and rigorous testing has catapulted us from a species-wide state of destitution to one of unimaginable wealth. That’s largely due to thousands of years of continued knowledge expansion and the pursuit of logical explanation. If science is the vehicle that brought us this far, then the fuel is undoubtedly…well, doubt.

This unique feature stands in sharp contrast to another primary way humans have explained the world: religion, which asks us to accept without questioning. Doubt may have been bad for Thomas, but Copernicus did wonderful things with it. There are few things as amusing as the rabid atheist who has not so much embraced doubt as become a cynic. Remember that uncertainty, regardless of its target, is the very heart of science.

A cursory glance at the past is all one needs to find examples of misplaced faith in science of the day. As the story of Dr. Semmelweis illustrates, there was a time when nearly all doctors were pretty damn sure that they didn’t need to wash their hands after handling dead bodies. In fact, they were offended by the notion.

More recently, Brian Nosek of the University of Virginia tried to replicate 100 studies appearing in top psychological journals; he and his team were unable to replicate about two thirds of them.

Treating scientific consensus axiomatically is a step in the wrong direction. We need to keep gathering information, and that information has to include research by iconoclasts in order to be well rounded. Remember that many widely held beliefs started out as heresies. Behind each of them was someone willing to come out against conventional wisdom, sometimes at great personal or professional risk.

The greatest minds of humanity used to believe in a static universe, phrenology, and many more things that we might find ridiculous today. So if skepticism is so demonstrably useful and deserved, why do people demonize each other for failure to follow the herd?

It’s politics, stupid.

Like basically anything today, science often finds itself mired in the ostentatious game of political signaling. Opinions and interpretations of scientific research are as much a part of political identity as a bumper sticker or a lawn sign. This is hugely unfortunate because it leads people to adopt dogmatic approaches to a process that should be objective.

Politics ruin science (and pretty much everything else) because everything is reduced to a zero-sum game: an us versus them scenario where concession is likened to defeat. They also reduce diversity of opinion and promote groupthink.

If you think I’m exaggerating, consider this: as people’s scientific literacy increases, their opinions on climate change polarize depending on their political affiliation. But that’s not all. According to the same study, conservatives who are more scientifically literate are also more likely to believe that there is a scientific consensus on global warming. Dan Kahan writes:

Accordingly, as relatively “right-leaning” individuals become progressively more proficient in making sense of scientific information (a facility reflected in their scores on the Ordinary Science Intelligence assessment, which puts a heavy emphasis on critical reasoning skills), they become simultaneously more likely to believe there is “scientific consensus” on human-caused climate change but less likely to “believe” in it themselves! 

While skepticism of climate change science is a markedly right-wing prejudice, those on the left are more likely to display similarly rock-ribbed opinions on fracking, GMO safety, and other areas that conflict with scientific consensus.

Politics are an inevitable part of living in a republic, but scientific debate loses integrity when we let our politics decide how we feel about science instead of the other way around. It’s divisive, but worse: it’s lazy and positively unscientific.

In an increasingly polarized country, we would do well to remember the humanity of our detractors. We also might make a conscious effort to both admit and overcome our biases, even as we argue with conviction.

Perhaps most importantly, we should stop acting like morality and argumentative position are inextricably linked. Doing so makes it that much easier to demonize people with differing opinions (If my opinion is moral and yours is different, it is less moral. Therefore, since you are putting forth an immoral opinion, you are evil)  and makes us far less capable of changing our own.

Leave the crusades in the 15th century.