In early April, the Pew Research Center, a non-profit fact tank based in Washington, DC, released The Changing Global Religious Landscape, a report on global demographic trends in religion, as part of its long-running Pew-Templeton Global Religious Futures project.
The report highlights fascinating trends in world population growth by religious group, focusing substantial attention on Christians and Muslims, the two religions with the largest number of adherents. Its key finding is that, while Christians are projected to remain the largest religious group until 2070, Islam is the fastest-growing religion, and births to Muslim mothers will outnumber births to Christian mothers by 2035.
In a sidebar on U.S. attitudes, the study also notes that while on the whole, Americans believe the share of the religiously unaffiliated will be largest, a plurality of U.S. Republicans and of Americans sixty-five and older believe Muslims will be the world’s largest religious group by 2050.
This, perhaps, inadvertently illustrates what can be so dangerous about this kind of data. In the past few decades, the United States and Europe have shown us how population trends, deep cultural fears, and racist ideology can intertwine. Projections that show U.S. whites losing their majority status have fed alt-right ideas of “white genocide.” The rise of Donald Trump has been attributed to a white “cultural anxiety” related to changing demographics. The idea that soon there will be more of them than us (whoever them and us might be) is both a persistent source of popular fear and a justification for racist and exclusionary policy. In an era of increasing white nationalism, anti-immigrant sentiment, and Islamophobia, data literacy and a solid understanding of the formulas behind these projections are crucial. Here are four key things to keep in mind when considering population growth and religion.
1. Population projections have both strengths and weaknesses.
Projections take what we know about current birth and death rates, and the way those rates have been changing over time, and extrapolate them into the future. In this way, they give us a better idea than almost any other method of what the world will look like if things keep going the way they are. But they cannot account for surprises, like the 2008 recession that caused a drop in fertility rates that has persisted for nearly ten years in the United States, or future breakthroughs in the fight against diseases like cancer or AIDS.
Projections involving rates of religious switching are especially tricky; as the report’s authors note, the trends in social processes, like conversion or loss of religion, are much more likely to change rapidly and unexpectedly, as compared with birth or death rates. The meaning of religious categories is also broad and fluid. People who consider themselves culturally aligned with a particular religion may not be counted as members of that religion, if they self-identify as atheist, agnostic, or “nothing in particular.”
This is especially important to remember when consuming media that repeats population projections like they are infallible prophecies of what is to come, or advances do-or-die policy changes to avert a perceived, on-coming demographic disaster.
2. Grouping people by religion carries with it the risk of essentializing differences.
Population projections by religion are useful in many ways. But, when interpreting them, it is crucial to understand that a large portion of the differences between religious groups are attributable to factors other than religion. Religious belief can certainly be a part of the fertility calculus, but other individual choices and social factors, including economic considerations, education, gender norms, the availability of career paths for women besides motherhood, and the extent to which those other paths are compatible with motherhood, play much larger roles.
The fertility rate amongst Christians in sub-Saharan Africa, where we will see the greatest growth in the world’s Christian population in the coming decades, compared to their co-religionists in regions, like Europe and North America, provides an especially clear illustration of this point. In sub-Saharan Africa, babies born to Christians exceeded deaths of Christians in every country – leading to an overall increase of 64 million for the region between 2010 and 2015 – whereas in Europe and North America, deaths outnumbered births to Christians in twenty-four of forty-two countries, leading to a net loss of 5.6 million.
These trends are no less true for Muslims. European Muslim women have far fewer babies than their co-religionists in the Middle East – and there is a lot of variation within the Middle East, too.
As this data also suggests, the world over, immigrants’ fertility and mortality rates resemble those of the society they move into. Furthermore, as the study notes, higher birth rates are partly a result of younger populations – if two groups are the same size, but one contains a higher proportion of people of childbearing age, it will almost certainly have a higher birth rate. This is a legacy of past population dynamics, not a Muslim plot to overrun Christians.
3. A decreasing white, European, and Christian share of the world population is the legacy of colonial power.
The world is currently cresting a wave of population growth brought about by the general fall in human mortality over the last 150 years. Life expectancy has steadily risen due to industrialization, public health and sanitation, and improvements in agriculture.
These advances have not, however, been distributed evenly. The development of an economic system in Europe that improved living standards in the late 1800s, particularly the availability of more nutritious and affordable food that vastly improved health and mortality rates for European populations, depended on the exploitation of colonies. Unsurprisingly, no such benefits accrued to colonized countries, where mortality rates remained high. While industrialization in Europe and North America also caused a very gradual fall in fertility, for a long time, births still slightly outpaced deaths in these countries. As a result, over many decades, Europe and North America became home to the majority of the world’s population.
After World War II and the end of colonialism, the mortality revolution went global, and the developing world finally had access to new technologies and public health practices they had helped create. But, while mortality rates decreased, the conditions that led to lower fertility – urbanization, industrialization, and widespread Western-style education – did not arrive as quickly in former colonies.
These states continued to experience a large differential in birth and death rates, resulting in a population explosion during the mid-twentieth century. This baby boom has led directly to today’s overwhelmingly young population in regions, such as sub-Saharan Africa and south Asia. Even as fertility has declined in these regions, growth rates will continue to outpace Europe and the United States – the large number of young people engendered by the population explosion ensure large raw numbers of births for the next few generations.
In short, the very same history that created the global north’s current political and economic hegemony also generated the population dynamics that ensure the numerical dominance of European-origin populations will not continue.
4. Use Metaphors with Caution
Demography deals with birth and death, growth and decline – features intrinsic to human experience and deeply entwined with the linguistic systems we use to express good and bad, strength and weakness. It is extremely hard to talk about populations growing older, experiencing fewer births, or gradually shrinking without using terms like “decline,” “aging,” or “dying out.” We should be careful to understand the rhetorical power of these words, however. Does a single period of low birth rates mean Christians in Europe, still hundreds of millions strong, are “dying out”? Does the strength and vibrancy of one community inevitably come at the expense of another?
We are used to thinking of growth as unequivocally desirable, but given the environmental challenges we face, is a gradual population decline necessarily bad? Though absolute decline in the world population is still a long way off, now is a good time to begin recognizing the difference between actual extinction and the tide of population growth receding from its crest.