Empty seats at a Catholic church in New York City, June 2014
Christopher Gregory / The New York Times

In the early years of the twenty-first century, religion seemed to be on the rise. The collapse of both communism and the Soviet Union had left an ideological vacuum that was being filled by Orthodox Christianity in Russia and other post-Soviet states. The election in the United States of President George W. Bush, an evangelical Christian who made no secret of his piety, suggested that evangelical Christianity was rising as a political force in the country. And the 9/11 attacks directed international attention to the power of political Islam in the Muslim world. 

A dozen years ago, my colleague Pippa Norris and I analyzed data on religious trends in 49 countries, including a few subnational territories such as Northern Ireland, from which survey evidence was available from 1981 to 2007 (these countries contained 60 percent of the world’s population). We did not find a universal resurgence of religion, despite claims to that effect—most high-income countries became less religious—but we did find that in 33 of the 49 countries we studied, people became more religious during those years. This was true in most former communist countries, in most developing countries, and even in a number of high-income countries. Our findings made it clear that industrialization and the spread of scientific knowledge were not causing religion to disappear, as some scholars had once assumed.

But since 2007, things have changed with surprising speed. From about 2007 to 2019, the overwhelming majority of the countries we studied—43 out of 49—became less religious. The decline in belief was not confined to high-income countries and appeared across most of the world. 

Growing numbers of people no longer find religion a necessary source of support and meaning in their lives. Even the United States—long cited as proof that an economically advanced society can be strongly religious—has now joined other wealthy countries in moving away from religion. Several forces are driving this trend, but the most powerful one is the waning hold of a set of beliefs closely linked to the imperative of maintaining high birthrates. Modern societies have become less religious in part because they no longer need to uphold the kinds of gender and sexual norms that the major world religions have instilled for centuries.

Although some religious conservatives warn that the retreat from faith will lead to a collapse of social cohesion and public morality, the evidence doesn’t support this claim. As unexpected as it may seem, countries that are less religious actually tend to be less corrupt and have lower murder rates than more religious ones. Needless to say, religion itself doesn’t encourage corruption and crime. This phenomenon reflects the fact that as societies develop, survival becomes more secure: starvation, once pervasive, becomes uncommon; life expectancy increases; murder and other forms of violence diminish. And as this level of security rises, people tend to become less religious. 

THE RISE AND FALL OF FAITH

Our earlier study, published in 2011, compared levels of religious belief measured as early as 1981 with findings from the latest surveys then available, from around 2007, bridging a period of roughly a quarter century. In each survey, respondents were asked to indicate how important God was in their lives by choosing a value on a scale ranging from one—“Not at all important”—to ten—“Very important.” 

Examining how a country’s level of religiosity changed over time led to some striking findings. A majority of the countries surveyed showed upticks in a belief in the importance of God. The largest increases were in former communist countries. For example, from 1981 to 2007, the mean score of the Bulgarian public rose from 3.6 to 5.7. In Russia, it rose from 4.0 to 6.0. In part, this growth in religiosity was a response to the severe decline of economic, physical, and psychological security experienced after the Soviet Union disintegrated; religion was filling the ideological vacuum left by the collapse of communism. Religious beliefs also increased in many developing countries outside the former Soviet Union, including Brazil, China, Mexico, and South Africa. On the other hand, religion declined in most high-income countries.

Since 2007, there has been a remarkably sharp trend away from religion. In virtually every high-income country, religion has continued to decline. At the same time, many poor countries, together with most of the former communist states, have also become less religious. From 2007 to 2019, only five countries became more religious, whereas the vast majority of the countries studied moved in the opposite direction. 

India is the most important exception to the general pattern of declining religiosity. The period of the study coincides roughly with the return to power of the Hindu nationalist Bharatiya Janata Party, whose brand of politics seeks to conflate national identity with religious identity. The BJP government has advocated policies that discriminate against the followers of other religions, particularly India’s large Muslim minority, polarizing communities and whipping up religious sentiments.

The most dramatic shift away from religion has taken place among the American public.

A dramatic shift away from religion has taken place among the American public. From 1981 to 2007, the United States ranked as one of the world’s more religious countries, with religiosity levels changing very little. Since then, the United States has shown one of the largest moves away from religion of any country for which we have data. Near the end of the initial period studied, Americans’ mean rating of the importance of God in their lives was 8.2 on a ten-point scale. In the most recent U.S. survey, from 2017, the figure had dropped to 7.0. For years, the United States had been the key case demonstrating that economic modernization need not produce secularization. By this measure, the United States now ranks as the 32nd least religious country for which we have data. 

Influential thinkers from Karl Marx to Max Weber to Émile Durkheim predicted that the spread of scientific knowledge would dispel religion throughout the world, but that did not happen. For most people, religious faith was more emotional than cognitive. And for most of human history, sheer survival was uncertain. Religion provided assurance that the world was in the hands of an infallible higher power (or powers) who promised that, if one followed the rules, things would ultimately work out for the best. In a world where people often lived near starvation, religion helped them cope with severe uncertainty and stress. But as economic and technological development took place, people became increasingly able to escape starvation, cope with disease, and suppress violence. They become less dependent on religion—and less willing to accept its constraints, including keeping women in the kitchen and gay people in the closet—as existential insecurity diminished and life expectancy rose. 

Secularization doesn’t happen everywhere at once; it occurs when countries have attained high levels of existential security, and even then it usually moves at a glacial pace, as one generation replaces another. It can even reverse itself, with societies becoming more religious if they experience prolonged periods of diminished security. Secularization has been gradually taking place since the nineteenth century, starting with the societies of western Europe and North America that were most secure economically and physically and then spreading to more and more parts of the world.

Although secularization normally occurs at the pace of intergenerational population replacement, it can reach a tipping point when the dominant opinion shifts and, swayed by the forces of conformism and social desirability, people start to favor the outlook they once opposed—producing exceptionally rapid cultural change. Younger and better-educated groups in high-income countries have recently reached this threshold. 

LOSING THEIR RELIGION

Several other factors beyond rising levels of economic and technological development help explain the waning of religion. In the United States, politics accounts for some of the decline. Since the 1990s, the Republican Party has sought to win support by adopting conservative Christian positions on same-sex marriage, abortion, and other cultural issues. But this political appeal to religious voters has had the corollary effect of pushing other voters, especially those who are young and culturally liberal, away from religion. It once was generally assumed that religious beliefs shaped political views, not the other way around. But recent evidence indicates that the causality can run the other way: panel studies have found that many people change their political views first and then become less religious. 

The uncritical embrace of President Donald Trump—a leader who cannot be described as a paragon of Christian virtue—by many prominent evangelicals has led other evangelicals to fear that young people will desert their churches in droves, accelerating an ongoing trend. The Roman Catholic Church, for its part, has lost adherents because of its own crises. Earlier this year, the Pew Research Center found that fully 92 percent of U.S. adults were aware of recent reports of sexual abuse by Catholic priests, and about 80 percent of those surveyed said they believed that the abuses were “ongoing problems that are still happening.” Accordingly, 27 percent of U.S. Catholics polled said that they had scaled back their attendance at Mass in response to these reports. 

But perhaps the most important force behind secularization is a transformation concerning the norms governing human fertility. For many centuries, most societies assigned to women the role of producing as many children as possible and discouraged divorce, abortion, homosexuality, contraception, and any sexual behavior not linked to reproduction. The sacred writings of the world’s major religions vary greatly, but as Norris and I have demonstrated, virtually all world religions instilled these pro-fertility norms in their adherents. Religions emphasized the importance of fertility because it was necessary. In the world of high infant mortality and low life expectancy that prevailed until recently, the average woman had to produce five to eight children in order to simply replace the population. 

A woman prays in a Hindu temple in Kolkata, India, March 2017
A woman prays in a Hindu temple in Kolkata, India, March 2017
Rupak De Chowdhuri / Reuters

During the twentieth century, a growing number of countries attained drastically reduced infant mortality rates and higher life expectancies, making these traditional cultural norms no longer necessary. This process didn’t happen overnight. The major world religions had presented pro-fertility norms as absolute moral rules and stoutly resisted change. People only slowly gave up the familiar beliefs and societal roles they had known since childhood concerning gender and sexual behavior. But when a society reached a sufficiently high level of economic and physical security, younger generations grew up taking that security for granted, and the norms around fertility receded. Ideas, practices, and laws concerning gender equality, divorce, abortion, and homosexuality are now changing rapidly.

This shift is quantifiable. Data collected in the World Values Survey over the years offer a glimpse of a deep transformation. The survey uses a ten-point scale based on each country’s acceptance of divorce, abortion, and homosexuality. The tipping point is around the middle of the scale, at 5.50: lower scores indicate that a majority of the country’s people harbor more conservative views, and higher scores indicate that a majority have more liberal views centered on individual choice. Around 1981, majorities in every country for which we have data supported pro-fertility norms. Even in high-income countries, the mean scores ranged from as low as 3.44 (Spain), 3.49 (the United States), 3.50 (Japan), 4.14 (the United Kingdom), and 4.63 (Finland) to as high as 5.35 for Sweden—then the most liberal country but with a score still slightly below the scale’s tipping point. But a profound change was underway. By 2019, Spain’s mean score had risen to 6.74, the United States’ to 5.86, Japan’s to 6.17, the United Kingdom’s to 6.90, Finland’s to 7.35, and Sweden’s to 8.49. All these countries were below the 5.50 tipping point when first surveyed, and all of them were above it by 2019. These numbers offer a simplified picture of a complex reality, but they convey the scale of the recent acceleration of secularization.

This trend has been spreading to the rest of the world, with one major exception. The populations of the 18 Muslim-majority countries for which data are available in the World Values Survey have stayed far below the tipping point, remaining strongly religious and committed to preserving traditional norms concerning gender and fertility. Even controlling for economic development, Muslim-majority countries tend to be somewhat more religious and culturally conservative than average.

THINGS WON’T FALL APART

For centuries, religion has served as a force for social cohesion, reducing crime and encouraging compliance with the law. Every major religion inculcates some version of the biblical commandments “Thou shalt not steal” and “Thou shalt not kill.” So it is understandable that religious conservatives fear that the retreat of religion will lead to social disarray, with rising corruption and crime. But to a surprising extent, that concern is not supported by the evidence.

Since 1993, Transparency International has monitored the relative corruption and honesty of government officials and business people around the world. Each year, this watchdog group publishes the Corruption Perceptions Index, which ranks public-sector corruption in 180 countries and territories. These data make it possible to test the actual relationship between religiosity and corruption: Is corruption less widespread in religious countries than in less religious ones? The answer is an unequivocal no—in fact, religious countries actually tend to be more corrupt than secular ones. The highly secular Nordic states have some of the world’s lowest levels of corruption, and highly religious countries, such as Bangladesh, Guatemala, Iraq, Tanzania, and Zimbabwe, have some of the highest. 

Clearly, religiosity does not cause corruption. Countries with low levels of economic and physical security tend to have high levels of religiosity and also high levels of corruption. Although religion may once have played a crucial role in supporting public morality, that role shrinks as societies develop economically. The people of religious countries are slightly more likely to condemn corruption than the people of less religious countries, but the impact of religion on behavior ends there. Religion may make people more punitive, but it does not make them less corrupt.

This pattern also applies to other crimes, such as murder. As surprising as it may seem, the murder rate is more than ten times as high in the most religious countries as it is in the least religious countries. Some relatively poor countries have low murder rates, but overall, prosperous countries that provide their residents with material and legal security are much safer than poor countries. It is not that religiosity causes murders, of course, but that both crime and religiosity tend to be high in societies with low levels of existential security. 

Religious countries actually tend to be more corrupt than secular ones.

The evidence suggests that modern societies will not descend into nihilistic chaos without religious faith to bind them, but that may not always have been the case. In early agrarian societies, when most people lived just above the survival level, religion may have been the most effective way to maintain order and cohesion. But modernization has changed the equation. As traditional religiosity declines, an equally strong set of moral norms seems to be emerging to fill the void. Evidence from the World Values Survey indicates that in highly secure and secular countries, people are giving increasingly high priority to self-expression and free choice, with a growing emphasis on human rights, tolerance of outsiders, environmental protection, gender equality, and freedom of speech. 

Traditional religions can be dangerously divisive in contemporary global society. Religions inherently tend to present their norms as absolute values, despite the fact that they actually reflect their societies’ histories and socioeconomic characteristics. The rigidity of any absolute belief system can give rise to fanatical intolerance, as the historical conflicts between Catholics and Protestants and Christians and Muslims have demonstrated. 

As societies develop from agrarian to industrial to knowledge-based, growing existential security tends to reduce the importance of religion in people’s lives, and people become less obedient to traditional religious leaders and institutions. That trend seems likely to continue, but the future is always uncertain. Pandemics such as the COVID-19 one reduce people’s sense of existential security. If the pandemic lasts for many years or leads to a new Great Depression, the cultural changes of recent decades might begin to reverse. 

But that shift remains unlikely, because it would run counter to the powerful, long-term, technology-driven trend of growing prosperity and increased life expectancy that is helping push people away from religion. If that trend continues, the influence that traditional religious authorities wield over public morality will keep shrinking as a culture of growing tolerance becomes ever stronger.

CORRECTION APPENDED (February 10, 2021)

An earlier version of this article cited a 2017 World Values Survey on religious beliefs that overstated an apparent decline in religiosity in the United States. The survey claimed that Americans’ mean rating of the importance of God in their lives dropped from 8.2 on a ten-point scale, in 2007, to 4.6, in 2017. In January, however, the WVS discovered an error in its data and revised the 2017 figure to 7.0. Thus, the United States has not shown the largest move away from religion of any country, as the article stated, but rather one of the largest moves away from religion. And the United States is not the 11th least religious country for which data are available, but rather the 32nd least religious country.

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