According to an international study done by William Bainbridge, atheism is frequent among people whose interpersonal social obligations are weak and is also linked to lower fertility rates in advanced industrial nations (See also: Atheism and social skills). See also: Atheism, women and children
Replacement fertility is the level of fertility that is required to sustain a population without any external inputs (see also: Population crash).
In human populations, replacement fertility is 2.1 children born per woman in a given population.
Sub-replacement fertility in secular populations: Academic research and journal publications
See also: Population crash
Eric Kaufmann on sub-replacement fertility
Eric Kaufmann teaches at Birbeck College, University of London and he specializes in how demographic changes affect the realms of religion/irreligion and politics. Kaufmann wrote about the problem of sub-fertility in the developed world in his book Whither the Child?: Causes and Consequences of Low Fertility. Kaufmann is an agnostic.
On December 23, 2012, Kaufmann wrote about the subject of global desecularization:
|“|| I argue that 97% of the world's population growth is taking place in the developing world, where 95% of people are religious.
On the other hand, the secular West and East Asia has very low fertility and a rapidly aging population... In the coming decades, the developed world's demand for workers to pay its pensions and work in its service sector will soar alongside the booming supply of young people in the third world. Ergo, we can expect significant immigration to the secular West which will import religious revival on the back of ethnic change. In addition, those with religious beliefs tend to have higher birth rates than the secular population, with fundamentalists having far larger families. The epicentre of these trends will be in immigration gateway cities like New York (a third white), Amsterdam (half Dutch), Los Angeles (28% white), and London, 45% white British. 
A study conducted by the Washington-based Pew Forum on Religion & Public Life says that Africans are among the most religious people on Earth. Africa has a high fertility rate and it is seeing a big population boom. According to the Institute For Security Studies: "Africa's population is the fastest growing in the world. It is expected to increase by roughly 50% over the next 18 years, growing from 1.2 billion people today to over 1.8 billion in 2035. In fact, Africa will account for nearly half of global population growth over the next two decades." See also: Religion and Africa and Global desecularization
At a conference Kaufmann said of religious demographic projections concerning the 21st century:
|“|| Part of the reason I think demography is very important, at least if we are going to speak about the future, is that it is the most predictable of the social sciences.
...if you look at a population and its age structure now. You can tell a lot about the future. ...So by looking at the relative age structure of different populations you can already say a lot about the future...
Kaufman wrote in his academic paper Shall the Religious Inherit the Earth?: Demography and Politics in the Twenty-First Century
|“||Today, values play a more important role in fertility behaviour, throwing the contrast between religious pronatalism and secular low-fertility individualism into relief. Over several generations, this process can lead to significant social and political changes. Early Christianity’s exponential rise during its gestation period from 30 to 300 A.D. has been traced to its superior demography (fertility, mortality and female sex ratio), which maintained a rate of growth similar to contemporary Mormonism: 40 percent per decade. For Christians, this led to a jump from 40 converts to 6 million inside three centuries. (Stark 1996) Christianity became the religion of an empire and a continent. In the United States, conservative sects increased their share of white Protestantism from roughly a third to two-thirds during the twentieth century – largely on the back of higher fertility. On the other hand, sects like the Shakers and Cathars, which permitted entry only through conversion, rapidly faded from the scene. Demographic religious revival is a medium and long-term phenomenon, but awareness of shifting population composition can lead to political soul-searching and instability well before the full impact of demographic change takes place. This is clear in ethnically-tense societies like Israel, Northern Ireland, Bosnia, Lebanon, Cote D’Ivoire or Assam.||”|
German researcher Michael Blume at University of Jena
Michael Blume, a researcher at the University of Jena in Germany, wrote about the sub-replacement level of fertility among atheistic populations: "Most societies or communities that have espoused atheistic beliefs have not survived more than a century." Blume also indicated concerning concerning his research on this matter: "What I found was the complete lack of a single case of a secular population, community or movement that would just manage to retain replacement level." See also: Atheism and sexuality
Ellis, Hoskin, Dutton and Nyborg journal article on fertility and secularism
The abstract for the 2017 journal article The Future of Secularism: a Biologically Informed Theory Supplemented with Cross-Cultural Evidence indicates:
|“||After reviewing the pertinent evidence and arguments, we examined some aspects of the secularization hypothesis from what is termed a biologically informed perspective. Based on large samples of college students in Malaysia and the USA, religiosity, religious affiliation, and parental fertility were measured using self-reports. Three religiosity indicators were factor analyzed, resulting in an index for religiosity. Results reveal that average parental fertility varied considerably according to religious groups, with Muslims being the most religious and the most fertile and Jews and Buddhists being the least. Within most religious groupings, religiosity was positively associated with parental fertility. While cross-sectional in nature, when our results are combined with evidence that both religiosity and fertility are substantially heritable traits, findings are consistent with view that earlier trends toward secularization ...are currently being counter-balanced by genetic and reproductive forces. ... secularism is likely to undergo a decline throughout the remainder of the twenty-first century, including Europe and other industrial societies.||”|
The researchers indicated: "Instead, over the long term, we predict that the most religious 'shall inherit the earth,' so to speak".
Reporting on the study, the Daily Mail indicated:
|“|| It was also found that Christians living in the US had 3.11 children and Catholics had 3.42.
...The team explained that there is evidence that genetically influenced personality traits, particularly agreeableness, lead to greater religious involvement, larger family size and greater communal investment in general.
'A recent meta-analysis of a large sample studies found that adults who score high on agreeableness tend to invest heavily in both religious and family life,' reads the study.
The authors of the study “envision a decline in secularism throughout the remainder of the twenty-first century, especially in industrialized countries.”
Pew Research: Fertility rates for atheist and the religious
Pew Research reported in 2015 that the average Christian woman in the world has 2.7 children.
In 2015, the Washington Post wrote about the United States and fertility rates for various religious groups:
|“||According to Pew's data, the average Mormon can expect to make 3.4 babies in his or her lifetime. Jews, Catholics, and most flavors of Protestantism have fertility rates ranging from 2 to 2.5. At the low end of the baby-making spectrum you've got atheists, with 1.6 kids, and agnostics, who average only 1.3.||”|
Fertility rates of countries with significant atheist populations
A replacement level of births in a country is 2.1 children per woman.
Secular European countries
- Sweden: 1.91 births per woman (2012)
- United Kingdom: 1.90 births per woman (2012)
- Finland: 1.80 births per woman (2012)
- Denmark: 1.73 births per woman (2012)
- The Netherlands: 1.72 births per woman (2012)
- Czech Republic: 1.45 births per woman (2012)
In 2014, the Pew Research Forum indicated that Europe will go from 11% of the world's population to 7% of the world's population by 2050.
Secular European country with a strong pro-natalist public policy
- France: 2.01 births per woman (2012)
Please see: France, a Pro-matalist Country
- Australia: 1.93 births per woman (2012)
Fertility rates of Asian atheistic countries
- China: 1.66 births per woman (2012)
- Japan: 1.41 births per woman (2012)
- Vietnam: 1.77 births per woman (2012)
- North Korea: 1.98 children born/woman (2014 est.)
Fertility rates of various countries
Babies born to non-religious mothers in decline
Global atheism, aging populations and falling fertility rates
See also: Global atheism and aging populations
Global atheism is facing significant challenges in terms of aging populations in East Asia and Europe and this will be a significant cause of desecularization in the 21st century (see: Global atheism and aging populations).
As atheist populations rise in age, the fertility rates of atheistic countries could drop further. The Rand Corporation indicates, "Nearly all European nations are experiencing long-term downtrends in fertility, and consequently, ageing of their populations. These demographic trends could have potentially damaging consequences for European economies."
Atheistic China and gender imbalance
China has the world's largest atheist population (see:China and atheism). The current atheist population resides mostly in East Asia (particularly China) and in secular Europe/Australia primarily among whites. See: Asian atheism and Western atheism and race According to a 2012 Worldwide Independent Network/Gallup International Association (WIN/GIA) poll, 47% of Chinese people were convinced atheists, and a further 30% were not religious. In comparison, only 14% considered themselves to be religious.
Due to sex-selection abortion and female infantcide, there is a gender imbalance within the Chinese population.
According to 2012 figures from the National Bureau of Statistics of the People's Republic of China, China’s sex ratio at birth (the number of boys born for every 100 girls) was as high as 118, while the sex ratio amongst the total population was about 105. The statistical data from China indicates that the gap between male and female at birth is far larger than the biologically benchmark ratio (a sex ratio at birth of around 105 males per 100 females).
- China says its gender imbalance 'most serious' in the world, Reuters, 2015
Center for the Study of Global Christianity: Atheists and religious population projections
According to Gordon-Conwell Theological Seminary's Center for the Study of Global Christianity, which has made projections up to the year of 2050, the percentage of the global population that are evangelical Christians/Pentecostals is expected to increase while the atheist population is expected to decline (see: Research on the projected number of atheists in the world).
Film documentary Demographic Winter: The decline of the human family
The film Demographic Winter: The decline of the human family focuses on the issue of sub-replacement fertility.
A review of the film documentary Demographic Winter declares:
|“||One of the most ominous events of modern history is quietly unfolding. Social scientists and economists agree -- we are headed toward a demographic winter which threatens to have catastrophic social and economic consequences. The effects will be severe and long lasting and are already becoming manifest in much of Europe. This ground breaking film draws upon experts from many different disciplines and reveals in chilling soberness the dangers facing society and the world's economies...||”|
- Will the religious inherit the earth? (Discusses Eric Kaufmann's work)
- American fertility rates for various worldviews, Washington Post
- Breeding for God, Prospect Magazine, 2006
- Battle of the babies, New Humanist (Kaufmann is interviewed by a secular humanist)
- Atheism's fertility deficit
- The inevitable decline of atheism
- Why people with no religion are projected to decline as a share of the world’s population
- "Atheism: Contemporary Rates and Patterns" (PDF)
- "Are Czechs the least religious of all? | Dana Hamplova | Comment is free | guardian.co.uk".
- Bainbridge, William (2005). "Atheism" (PDF). Interdisciplinary Journal of Research on Religion. 1 (Article 2): 1–26.
- Battle of the Babies by Caspar Melville, The New Humanist
- Whither the Child? Causes and Consequences of Low Fertility, University of Virginia, Department of Sociology
- 97% of the world's population growth is taking place in the developing world, where 95% of people are religious, Tuesday, April 30, 2013
- Why so many Africans are religious: Leo Igwe
- Africa’s population boom: burden or opportunity?, Institute For Security Studies
- Eric Kaufmann - Religion, Demography and Politics in the 21st Century
- Shall the Religious Inherit the Earth?: Demography and Politics in the Twenty-First Century by Eric Kaufmann, Belfer Center, Harvard University/Birkbeck College, University of London (PDF)
- Atheist: A dying breed as nature favours faithful
- The Future of Secularism: a Biologically Informed Theory Supplemented with Cross-Cultural Evidence by Lee Ellis, Anthony W. Hoskin, Edward Dutton and Helmuth Nyborg,Evolutionary Psychological Science 08 March 2017, pp 1–19
- [Is atheism dying out? Study finds religious people reproduce MORE due to their lack of belief in contraception] by STACY LIBERATORE, Daily Mail, 15 March 2017
- Study Claims Atheists Could Die Out Because They Love Birth Control So Much by Thomas Phippen, Daily Caller, 2017
- The Future of World Religions: Population Growth Projections, 2010-2050, Pew Research, 2015
- Charted: The religions that make the most babies, Washington Post
- Kochhar, Rakesh (February 3, 2014). "10 projections for the global population in 2050". FactTank/Pew Research Center website.
- Low Fertility and Population Ageing, Rand Corporation
- "The largest atheist/agnostic populations". Chris & Terri Chapman. Countries with the largest atheist populations.
- Top 50 Countries With Highest Proportion of Atheists / Agnostics (Zuckerman, 2005)
- A surprising map of where the world’s atheists live, Washington Post By Max Fisher and Caitlin Dewey May 23, 2013
- Fisher, Max and Dewey, Caitlin (May 23, 2013). "A surprising map of where the world’s atheists live". The Washington Post website.
- "Global Index of Religiosity and Atheism", Gallup. Retrieved on 2012-11-28.
- National Bureau of Statistics of China, Beijing, China
- Poston, L. D., & Glover, S. K., Too many males: marriage market implications of gender imbalances in China, 2005
- Demographic Winter: The decline of the human family - Amazon