The world's poorest nations are also some of its most religious – but does that mean religion can't flourish in a prosperous society?

Gregory Paul doesn't think it can. After constructing a "Successful Societies Scale" that compared 25 socioeconomic indicators against statistics on religious belief and practice in 17 developed nations, the Baltimore-based paleontologist concluded in a 2009 study that "religion is most able to thrive in seriously dysfunctional societies."

Paul, who is a freelance researcher not affiliated with any institution, compiled data on everything from homicide rates and income inequality to infant mortality and teenage pregnancies and found that the societies that scored the best on socioeconomic indicators were also the most secular.

"The correlation between religiosity and successful societies is somewhere around 0.7. Zero is no correlation and one is a perfect correlation, so it's a really good correlation, and it's not just an accident," he told CBC News.

"There's no situation where you have a really highly religious nation that's highly successful socially."

Paul's intention in creating the scale was to challenge the idea that religion is universal and innate to the human condition, and to show that societies that don't believe in God are not doomed, as some religious conservatives would have people believe.

"Religion is highly variable, and therefore we need to ask why is it sometimes popular and why it isn't," Paul said. "One thing we do know is that it's only popular in societies that … have enough rate of dysfunction that people are anxious about their daily lives, so they're looking to the gods for help in their daily lives.

"It's not fear of death that drives people to be religious, and it's not a God gene or a God module in the brain or some sort of connection with the gods; it's basically a psychological coping mechanism."

Religion on decline in West

Belief in God and participation in religious services have been on the decline in recent decades in most First World nations but have remained high in developing countries. Between 1947 and 2001, belief in God declined by 33.6 per cent in Sweden, 19.9 per cent in Australia and 7.2 per cent in Canada, according to an analysis of social science surveys done by Harvard sociologist Pippa Norris and University of Michigan political scientist Ronald Inglehart.

Data for developing countries does not go back as far, but recent opinion polls suggest religiosity has remained high. The 10 most religious countries on the 2012 WIN-Gallup International Religiosity and Atheism Index all had 85 per cent or more of respondents identifying as "a religious person," and all were countries with a per capita income of less than $14,100 US.

Source: WIN-Gallup International

When Norris and Inglehart pooled 20 years of results from the World Values Survey, which regularly polls dozens of countries on social science questions, they found that in agrarian societies, 44 per cent of people said they attended church at least once a week compared to 25 per cent in industrial and 20 per cent in postindustrial societies. They also found that nations that scored low on the Human Development Index, which measures health, education and living standards, tended to be those with the highest rates of participation in religious services and prayer.

More recent polls have found similar divisions between rich and poor nations. The 2009 Gallup Inc. religion survey, which sampled about 1,000 people in each of 114 countries, found that among nations with a per capita income of less than $2,000, 95 per cent of respondents, in the median, answered "Yes" to the question: "Is religion an important part of your daily life?"

In countries with per capita income of more than $25,000, 47 per cent of respondents answered "Yes." In Canada, 42 per cent of respondents said religion was important.

Bangladesh, Niger, Malawi and Yemen had some of the strongest positive responses (99 per cent) while Sweden (17 per cent), Denmark (19 per cent), Japan (24 per cent) and Estonia (16 per cent) — where religion was suppressed under the former Soviet regime — had some of the weakest.

People walk past the Great Mosque in the ancient desert city of Agadez, Niger. Ninety-nine per cent of respondents to a Gallup Inc. survey in Niger said religion was an important part of daily life. (Tientan Ling/Reuters)

"I was a little surprised … how strongly it correlated with income, but it definitely corresponds to other research that has shown that societies tend to grow more secular as they modernize and as living standards improve," said Steve Crabtree, a research analyst with Gallup Inc. (a separate entity from WIN-Gallup International).

(The Gallup and the WIN-Gallup International polls have a margin of error of around +/- 3 to 5 per cent.)

Most vulnerable are often most religious

Sociologists have argued that the social benefits of religion take on greater importance, the fewer resources and the less control people have over their own lives.

"Religion becomes less central as people's lives become less vulnerable to the constant threat of death, disease and misfortune," Norris and Inglehart write in their 2004 book, Sacred and Secular: Religion and Politics Worldwide.

"As lives gradually become more comfortable and secure, people in more affluent societies usually grow increasingly indifferent to religious values, more skeptical of supernatural beliefs and less willing to become actively engaged in religious institutions."

In poor countries, religious institutions often provide essential services such as education and health care, and the social networks that faith communities provide can be crucial in times of crisis.

"In the richer countries, people are less likely to face existential threats … so they have more opportunity for fulfillment outside of religion," Crabtree said.

But it's more than just an accumulation of wealth that makes a country more secular, sociologists say.

"The United States is one of the wealthier societies, and yet, it's still quite religious," said Phil Zuckerman, a sociology professor at Pitzer College in Claremont, Calif., who has studied secularization in Scandinavian countries and wrote a book about it called Society Without God.

"I think it's when you have what we might call 'existential security' — so, wealth and prosperity are part of that, but by that we [also] mean the bulk of people in society have access to housing, health care, jobs. They live in a relatively stable, democratic society without much in the way of existential threats to their lives or their culture."

It's no accident, say some sociologists, that some of the world's least religious people live in nations like Denmark, Sweden, Germany, France and the Netherlands, all highly egalitarian societies with strong social safety nets.

Education is another aspect of prosperity that plays a role in religiosity. The WIN-Gallup International poll, which surveyed close to 52,000 people in 57 countries, found that religiosity decreased as education level increased. The proportion of people who identified as religious was 16 per cent lower amid respondents with a post-secondary education than amid those with less than a secondary education.

U.S. the outlier among rich nations

Not all countries conform neatly to the correlation between rising secularism and prosperity — Italy and Ireland, for example, are well-off First World countries where religiosity remains high, while China and Vietnam, whose regimes are officially atheist, are poor nations that are also among the most secular.

But the U.S. is the most conspicuous outlier among wealthy nations:

• 80.8 per cent of Americans believe in God and always have, a higher percentage of the population than in any other affluent nation polled in the 2008 International Social Survey Programme (ISSP) religion survey (France had 28.9 per cent lifelong believers, for example, while Britain had 36.7 per cent).
• 60.6 per cent of Americans say they have no doubt God exists, compared to 15.5 per cent in France and 16.8 per cent in the U.K. (ISSP).
• 4.4 per cent don't and never have believed in a God, compared to 24.3 in France and 20.0 in the U.K. (ISSP).
• 24.2 per cent attend religious services once a week, compared to 5.6 per cent in France, 10.0 per cent in the U.K. and 17.7 per cent in Canada, according to the 2006 World Values Survey.

"Europe and the United States seem to be going in very different directions," said Marcus Noland, a senior fellow at the Peterson Institute for International Economics in Washington, D.C., who has written about religion and economic growth.

"One of the arguments is that the United States has a much livelier and open market for religion than do, say, countries in Scandinavia, where you have established churches."

Catholic devotees pray at the Shrine of Our Lady of Martyrs in Auriesville, N.Y. The United States has not seen the same decline in religiosity as other wealthy nations. (Lucas Jackson/Reuters)

But Zuckerman and other sociologists attribute the U.S.'s outlier status to socioeconomic inequality.

"We have 50 to 60 million people without health insurance; we have the highest child poverty rates of the industrialized democratic world; the greatest gap between rich and poor of the industrialized democratic world; we have increasing inequality and, voilà, we also have a strongly religious society … that can't be accidental."

But Noland warns against drawing too many conclusions from polls that really only offer a brief snapshot in time.

"The question is: does it hold over time?" he said. "You may be in a period of great awakenings in which you broadly had an intensification of religiosity, which then recedes."

'Prosperity is one strong causal factor in helping to explain why religion corrodes.'— Phil Zuckerman, sociologist

It's impossible to prove that worsening socioeconomic factors cause religion to increase or vice versa, because there is not sufficient data going far enough back in time and so many different elements, including and especially demographics, are at play, Noland said.

"It's a more complex psychological and social phenomenon than just looking at a snapshot of cross-state data or even cross-income data and saying religion either keeps you poor or not being religious gets you rich," he said.

Norris and Inglehart and other sociologists concede that the erosion of religious beliefs and practices is shaped by long-term changes and countless influences, including a country's cultural and religious traditions.

"Prosperity is one strong causal factor in helping to explain why religion corrodes," Zuckerman said. "Is it the only one? No. Is it always going to result in secularization? No. But it's one strong causal factor among many."