Fertility and Faith

Fertility and Faith July 11, 2016

I have written a good deal about the relationship between demographics and religious loyalties, and this theme has critical implications for the future development of all the world’s faiths. This topic will probably be the theme of my next book, so let me take the opportunity offered by the blog format to lay out some of the core ideas and case studies here.

Briefly, I will be discussing the direct relationship between the fertility rates of a community and its degree of religious fervor and commitment. The lower the fertility rate, the smaller the family size, the greater the tendency to detach from organized or institutional religion. Fertility rates supply an effective gauge of trends towards secularization.

Of itself, such an idea is not entirely new, and it has been explored to some degree as a causal factor in the secularization of contemporary Western Europe, Recent projections, though, strongly suggest that European-style declines in fertility are now affecting much of the globe, and that those trends will become ever more marked over the next three or four decades. If that is correct, then we would expect the religious character of those other non-European areas to be transformed much like Europe itself, that is, in the direction of sweeping secularization.

That does not of itself supply any kind of death warrant for the great religions, either in Europe or beyond. Rather, in order to accommodate to new social trends, religions have to evolve new means of presenting their views, to address societies where large families with abundant children are no longer the norm. Probably, they will develop different emphases concerning morality and sexuality; and also about the relative roles of clergy and laity in the faith’s institutional structures. We need to think very carefully about our definition of secularization, which is not necessarily identical with changes in the institutional structures of given faiths.

Whatever specific changes we might expect, though, demographic changes are certain to cause radical transformations in all religions.

Let me expand on some of those ideas.

Demographic factors go far towards explaining the changing shape of the world’s religious map, and help us understand the kinds of religious faith and practice that prevail in particular regions. Without invoking a rigid demographic determinism, these factors do have a close relationship to secularization on the one hand, and fervent activism on the other.

Much of the Euro-American world today is profoundly secular, to the extent that some scientific surveys project the total evaporation of faith of all kinds from several nations by the end of the present century. A study reported to the American Physical Society in 2011 predicted that by the end of the present century, nine nations would be entirely free of religion, namely Australia, Austria, Canada, the Czech Republic, Finland, Ireland, the Netherlands, New Zealand, and Switzerland. Whether or not such predictions are valid, the reasons underlying that religious decline have some predictive value for understanding the world’s religious climate.

One critical statistic for understanding any society is its fertility rate, the average number of children born to a typical woman over the course of her lifetime. If that figure is around 2.1 children per woman, then the population will remain broadly stable, and that level is termed “replacement rate.” If the rate is much higher than that, say 5 or 6 per woman, then we will see a rapidly expanding population with many young people and young adults, with all the restlessness and turbulence that suggests. A fertility rate below 2.1 will produce a contracting population and an aging society. (Death rates are also significant of course, but less so for present purposes).

Not coincidentally, the Europe that has become so secular has also, since the 1960s, pioneered an epochal demographic revolution of historically low fertility rates. Those rates are at their lowest in such countries as Spain and Italy, where they stand around 1.3 or 1.4, while some German regions show unprecedented historic lows of 0.8. The fertility rates of nations like France and Great Britain are higher, approaching replacement, but that is because of the high fertility of immigrants. The rates of old-stock white populations remain universally low.

I quote from the 2013 World Population Data Sheet:

Europe’s birth rate has plummeted to an unexpectedly low level in the past few decades. Europe’s population of 740 million is projected to decrease to 726 million by 2050, but even that lower number depends on whether immigration helps to stall a more-rapid decline. Today, women in Europe average only 1.6 children, compared to 2.6 in 1960. This low fertility has created unprecedented aging. In Europe, only 16 percent of the population is below age 15. Compare that to 41 percent in Africa and 25 percent in Asia. Europe’s population ages 65 and older is projected to rise to 27 percent by 2050.

That demographic change has complex consequences for religious change, although there is no simple chain of causation. Nor is it easy to distinguish cause from effect. The fact of having fewer children is itself a powerful secularizing force. If a typical woman has six or seven children, that family is probably going to be closely tied to a complex network of religious institutions, to church and parish school, to shared rituals and celebrations like First Communion and confirmation classes. Take the children out of the picture, eliminate the need for mass socialization, and watch church attendance collapse, followed closely by vocations to the priesthood and clergy. And then watch a generation of youngsters brought up without even a nodding acquaintance with, or respect for, any form of organized faith.

Fertility inevitably falls when women entering the workforce become independent social and political actors. As such, they are reluctant to heed the church’s strictures on their moral conduct, particularly in matters like divorce, contraception and abortion. Also, the reason why people have fewer children in the first place is often because they no longer feel subject to the demands of religion and family pushing them to reproduce as their ultimate goal in life.

Society becomes atomistic and individualist rather than organic and traditional. A society in which people regard relationships as intended chiefly for companionship and mutual satisfaction is also more open to unconventional sexual arrangements, and to once unthinkable innovations such as same sex marriage. Finding themselves in constant disagreement with church stances on politics – seeing the churches apparently on the wrong side in all the incessant culture wars – people become disaffected from organized religion.

Even in once solidly Catholic countries, we see the advance of contraception, abortion, and same sex marriage, and a precipitous decline in church attendance and participation. If demographics does not offer a complete account of European secularization over the past half-century, then it is a component of the story that we neglect at our peril. The  correlation between faith and fertility is genuine and significant.

Conversely, high fertility rates correlate neatly to instability, and also to religious commitment. This linkage is apparent if we look at the societies with the world’s highest fertility rates, which are found across Muslim North Africa and Southern Asia, but also Christian black Africa. The very highest rates are found in such perennial sources of grim headlines as Iraq, Afghanistan, Somalia, Chad, and the Gaza Strip. These areas represent the absolute antithesis of the pacific and secular trends we have witnessed in Europe. Those pious lands have no shortage of uneducated adolescents prepared to shoulder a Kalashnikov in the cause of God, family and honor. They define their problems in strictly religious terms, and readily join millenarian movements that offer them a glimmer of hope, in this world or the next.

Recent global projections suggest that the kind of transformations that I have described will soon affect virtually the entire world – with the very significant exceptions of Africa and some regions of south-west Asia. Across Latin America and East Asia, fertility rates are rapidly plummeting to Spanish and Italian rates, which are also now found across large sections of India.

The “African Exception” is critical for scholars of Christianity. A few years ago, I projected that by 2050, Africa would contain the world’s largest Christian population, and that around one-third of Christians would live on the African continent. That was quite apart from African migrants in the global diaspora, chiefly in Europe and North America. Today, though, that projection seems conservative. African numerical dominance within that faith will arrive sooner than I argued, and will be still more sizable.

It is certain that these changes will have their religious consequences, although as yet, they have attracted the attention of very few observers. Most significantly, Mary Eberstadt has eloquently stressed the role of shrinking family size in secularization (How the West Really Lost God: A New Theory of Secularization, Templeton Press, 2013). I do have some disagreements with her, above all that the changes she describes are by no means confined to the Euro-American world. Even her admirable work leaves lots more to say about what is, in fact, a developing global story.

I also respectfully disagree with the conclusions of one major work in this area, Eric Kaufmann’s 2011 book, Shall the Religious Inherit the Earth? Demography and Politics in the Twenty-First Century. While acknowledging the steep declines in fertility worldwide, Kaufmann suggests that highly religious families will continue to have large numbers of children, so that future societies will actually be more rather than less religious. I disagree with his view for several reasons, not least that many societies that currently have very high fertility can swiftly change in the opposite direction: witness Spain, Italy and Ireland over the past four decades. If highly religious communities currently hold out against the general trend, I would suggest that this resistance is only temporary, and might last for a generation or so. It will not detract from long term declines in institutional faith – and in some areas, from outright secularization.

In summary, I think the demographic dimension is critical to debate about the world’s great religions and their imminent prospects.

More in future columns.


There are lots of sources for demographic data, including the CIA Factbook. One convenient example is the Population Reference Bureau, with its annual World Population Data Sheets.

Apart from the books mentioned above, major studies include Phillip Longman, The Empty Cradle: How Falling Birthrates Threaten World Prosperity And What To Do About It (Basic Books, 2004), and Jay Winter and Michael Teitelbaum, The Global Spread of Fertility Decline: Population, Fear, and Uncertainty (Yale University Press, 2013). On the international ramifications of these trends, see especially Susan Yoshihara and Douglas A. Sylva, eds., Population Decline and the Remaking of Great Power Politics (Potomac Books, 2011). See also Ted C. Fishman, Shock of Gray: The Aging of the World’s Population and How It Pits Young Against Old, Child Against Parent, Worker Against Boss, Company Against Rival and Nation Against Nation (Scribner, 2010). Now that’s a subtitle.


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