Religiosity and atheism: revised estimates for 1980-2020

In previous posts, I have summarized various analyses of the World Values Survey (WVS) and the European Values Study (EVS), altogether including more than 110 countries, and focusing on trends and differences religious affiliation, religious beliefs and practices, as well as traditional and modern values.  I examined the prevalence of religious people, non-religious people and atheists across 110 countries in 2020 here, and trends from 1980 to 2020 here.

Checking in on the World Values website earlier this year, I discovered that the World Values Survey dataset has been updated to fix some errors in the coding of data for. Some data collected using a mobile phone app in the most recent US survey was incorrectly coded and this mainly affected the religiosity categories.  Comparison of the US prevalences for religiosity show that the coding errors resulted in an overestimate of the atheist and non-religious categories as shown in the following table:

Comparison of religiosity prevalence estimates
 for USA in year 2020

This post provides updated estimates of religiosity levels and trends for countries, regions and world based on the 2021 release of the combined data for the WVS and EVS in the Integrated Values Surveys (IVS) 1981-2021 [1-3]. In carrying out these updates, I also addressed some definitional issues which have resulted in mostly slight changes to estimates for other countries.

The atheist and other categories of religiosity are constructed from the following survey questions:

Survey questionResponse categories
Are you a religious person?A religious person / Not a religious person / A confirmed atheist
Importance [in life: religion] Very, Rather / Not very / Not at all
How often do you attend religious services?More than once a week / Once a week / Once a month / Only on special holy days / Once a year / Less often / Never, practically never
Pray to God outside of religious services?More than once a week / Once a week / At least once a month / Several times a year / Less often / Never
Belief in godYes / No / Don’t know
Importance [in life: God]1 (Very important), 2…9, 10 (Not at all important)
Religious affiliationNone, 9 or more religion/denomination categories, Other

Estimates of atheism prevalence based on WVS/EVS, or the Pew or Gallup surveys addressing this question often quote statistics based on question categories such as “confirmed atheist” or “not religious” or “religion: none” (see Wikipedia for more information on these). The first of these provides low estimates of overall atheist prevalence, since the qualifying adjective “confirmed” will result in many atheists avoiding this category. In the full IVS dataset (645,249 respondents), 5.5% of respondents said they were “confirmed atheists” whereas 13.3% stated they did not believe in God and a further 3.2% did not know whether they believed in God (note these figures are unweighted for sampling or country population size at this stage). In contrast, the “non-religious” and “religion: none” categories will include theists who have rejected organized religion as well as atheists.

I suspect the term “confirmed atheist” is intended to exclude agnostics (who say they don’t know whether God does or does not exist. I prefer to use the modern widely accepted definition of atheism as “lacking belief in God or gods”. This will include gnostic atheists (those who say they know gods don’t exist) and agnostic atheists (those who say they don’t know whether God or gods exist and lack a belief in any). So for the belief in God question I have recoded “Don’t know” to “No”, as a person is highly unlikely to have a belief in God which they don’t know about. This resulted in an overall distribution of 79%  Yes, and 21% No (comprised 16.8% No and 4.0% recoded Don’t know).

There is an additional complexity in defining religiosity for people who are affiliated with non-theist religions such as Buddhism, Jainism, or Confucianism. This mainly relates to Asian countries, as the proportion of people who are belong to non-theist religions is generally small in other regions. The religiosity categories I defined for previous analyses moved practicing and non-practicing non-theist religious people from the atheist category to the relevant religious categories, meaning that the atheism category essentially excluded atheists who practiced non-theist religions. Asian religious practice tends to be syncretic, so for example, many people in Japan practice follow both Buddhist and Shinto religious practices. Additionally, in some cultures and non-theist religious traditions, there are mythic gods and for many people, the historical Buddha is essentially considered to be a god. In the IVS dataset, 61% of Buddhist say they believe in God, and 39% say they do not believe in God.

To obtain a complete estimate of the prevalence of atheism (those who lack a belief in God or gods), I have assigned all people who do not believe in God to the atheist category. This will thus include some religious people who practice non-theist religions. The practicing religious and non-practicing religious categories who thus be understood to refer to religious practice/belief including a belief in God or gods, including some but not all followers of non-theist religious traditions.

The four religiosity categories have thus been defined as:

Practicing religious person: A religious person who believes in God and is practicing*, OR a non-religious person who believes in God, is practicing, and rates the importance of God in range 1-5.

Non-practicing religious person: A religious person who believes in God and is non-practicing OR a non-religious person who believes in God, is non-practicing, and rates the importance of God in range 1-6.

Non-religious: A non-religious person who believes in God but rates the importance of God as 7-10 at the not important end of a 10-point scale.

Atheist: A “confirmed atheist” and/or does not believe in God

* Respondents are classified as “practicing” if they attend religious services or pray to God outside of religious services at least once a month. Otherwise, they are classified as non-practicing.

For the 110 countries with IVS survey data for years 2000 or later, the prevalences of the four religiosity categories across survey waves were projected forward to 2020 (Endnote a). The following plot shows the estimated prevalence of all religiosity categories in 2020 for countries ranked in descending level of irreligion (atheist + non-religious).

There are 18 countries where more than half the population are estimated to be atheist in 2020. These include China,  South Korea, Japan, Vietnam and Thailand, all Asian countries with Buddhist and non-theist religious traditions. They also include all the Scandinavian countries and European countries such as France, the Netherlands and the United Kingdom, as well as Australia and New Zealand.     At the other end are six countries where the prevalence of irreligion is estimated at less than 1% of the population.

Full time series of religiosity trends from 1980 to 2020 were imputed for the 110 countries using the same methods as developed for the earlier analyses (see endnote a). The updated trends are generally similar to those previously posted (see here), except for the USA. The revised data for the USA shows that the prevalence of atheism has increased rapidly in the 21st century from around 6% to almost 23% in 2020 and the prevalence of non-religious has also increased from 2.2% to 6.9%. 

The prevalence of irreligion (atheists and non-religious) has increased in the USA by an estimated 21.5 percentage points over the last two decades, the fourth largest increase of any country included in this analysis. The largest increase occurred in neighboring Canada with a 36.7% increase since year 2000.  Apart from two Asian countries (South Korea and Singapore) and Hong Kong, all the other countries in the top 20 for increase in irreligion since 2000 are high income countries. And apart from Chile, Australia and New Zealand, all of these are in Europe and North America.

To compute regional and global trends in religiosity, I have also imputed religiosity for 75 countries not included in the IVS using data from Win/Gallup and Pew Research Centre surveys (Endnote b). These 75 mostly small countries (apart from in Africa) account for 8% of the world population, mostly in the Islamic East and Sub-Saharan Africa (23% and 41% respectively of the populations of those regions).

I have computed revised trends for the 11 culture zones used in previous posts. These are based on those originally defined by Welzel [4], with one modification. Because Australia’s and New Zealand’s culture values are much closer to the countries of the Reformed West than to those of the USA and Canada, I have included Australia and New Zealand in the Reformed West and renamed the New West as North America (see Endnote c for details). In summary, these are:

Reformed West — Western European societies strongly affected by the Reformation;
North America — USA and Canada;
Old West — Mostly Catholic parts of Western Europe being core parts of the Roman Empire;
Returned West — Catholic and Protestant parts of post-communist Europe returning to the EU;
Orthodox East — Christian Orthodox or Islamic parts of the post-communist world, mostly parts of former USSR;
Indic East — Parts of South and South East Asia under the historic influence of Indian culture;
Islamic East — Regions of the Islamic world formerly parts of the Arab/Caliphate, Persian and Ottoman empires;
Sinic East — Parts of East Asia under the historic influence of Chinese culture ;
Latin America — Central and South America and the Caribbean;
Sub-Saharan Africa — African countries south of the Sahara.
Oceania — Pacific Island states with predominantly Melanesian and Polynesian populations

The following plots show estimated religiosity trends for the world as a whole and for these 11 culture zones:

These plots illustrate the extreme diversity of religiosity trends across regions. Western countries (Reformed West, Old West, North America) are characterised by rapidly rising prevalence of atheism and corresponding decline in practicing religious. The former Eastern bloc countries (Returned West, Orthodox East) are characterised by a large drop in atheism prevalence and corresponding rise in religious categories following the collapse of the Soviet Union around 1991. More recently, atheism is rising and practicing religious falling in the Returned West, following a similar path to that taken by Western Europe.

The Orthodox East has had continuing decline in atheism and the non-practicing religious have become the dominant group at around 55% of the population, far more than the practicing religious. A 2018 Pew Research Center Report [5] examined this more closely and found that for most people in the former Eastern bloc, being Christian (whether Catholic or Orthodox) is an important component of their national identity, with many people embracing religion in the post-Communist period as an element of national belonging, even though they are not highly religious.

Latin America, the Islamic East and Sub-Saharan Africa are the “religious” culture zones characterised by very high prevalences of practicing and non-practicing religious people and very low prevalences of non-religious and atheists. The Indic East also has very low prevalences of the irreligious, but in contrast to the other “religious” zones, has had a shift from practicing to non-practicing religious. This may very well be largely reflecting the increasing levels of Hindu nationalism in India.

Iran and other Islamic countries generally report very low levels of atheism, 2.4% on average, and I suspect this is lower than reality because of the quite severe social and legal consequences in many Islamic countries. The WVS uses telephone interviews and its quite likely irreligious respondents would be fearful of being identified if they respond honestly to a telephone interview. A recent internet survey provides some support for this concern. A June 2020 internet-based survey collected responses from 40,000 Iranians living in Iran. Respondents took part in the survey anonymously, and would have felt safer to express their real  opinions than in telephone surveys or surveys conducted at respondents’ residence.

The contrast with the results of the most recent 2020 World Values Survey for Iran are extreme. The latter found that 43% of Iranians are practicing Muslims (similar to the online survey estimate for total Muslims, 53% are non-practicing and only 1.5% say they do not believe in God. In the WVS, 91% say they believe in life after death, 92% believe in heaven and 88% believe in hell. The online survey found that over 60% said they did not perform the obligatory daily Muslim prayers. This is in the same ballpark as the 53% who were classified as non-practicing in the WVS.

Reading between the lines of the WVS, and taking into account the severe consequences of being apostate or atheist in Iran, it supports the conclusion of Arab and and Maleki [6] that Iran is becoming much more secular. Around 53% of respondents in their online survey reported coming from practicing religious families but losing or changing their religion in their lifetime. This increasing secularity is also supported by the evidence of dramatic declines in the fertility of Iranian women over recent decades, with population growth in 2020 dropping below 1%. It’s quite likely that real levels of irreligion are higher in many other Islamic countries than the survey data suggest.

The Sinic East is of course dominated by China. Around 1980, apparently equal numbers of people in this region identified as atheist and non-religious. There has been a dramatic drop in the non-religious prevalence with a corresponding rise in the prevalence of atheism. The overall prevalence of irreligion has remained fairly stable and high. Its difficult to know what to make of this, or whether it reflects any real change, given the possibility that the Chinese language version of the WHS questions may have changed in some way over time, or their interpretation has changed given the overall lack of fit of the WVS religious questions with the non-theist religions that are most common in China.

At global level, the prevalence of practicing religious has barely changed over the last 40 years, as has the prevalence of atheism, but there has been a shift from non-religious to atheist and to non-practicing religious, the latter reflecting mainly the change in former Soviet bloc countries. The relatively small changes in prevalence of religiosity at global level over the last 40 years conceal quite substantial changes in developed countries and in former Soviet countries, in opposing directions. The following table summarizes global changes in the prevalence of religiosity categories over the 40-year period 1980 to 2020.

The overall global prevalence of irreligion (atheist plus nonreligious) has declined somewhat, but a substantially higher proportion of the irreligious identify as atheist in 2020 compared to 1980. Is irreligion likely to increase in the future. If the economies of developing countries continue to grow, with decreasing levels of poverty, and education levels continue to improve, it is likely that religiosity in these countries will decline in the longer term. But if the pandemic and global heating crises derail the historical development trends, then population growth due to the higher fertility levels of Islamic and African countries will ensure that the overall religiosity of the world will increase in the future. 

  If on the other hand, the very low levels of irreligion in Islamic countries and Africa do not increase, then the higher fertility levels of these regions will ensure that the overall religiosity of the world will increase in the future. In an era of joint global environmental and pandemic crises, with rising populism and rejection of science and global institutions, its entirely possible that the developing countries will not pass through the equivalent of the Western Reformation resulting in freedom of thought and religion and decreasing levels of premodern religious values (see previous post here).


a. Interpolation and projection of religiosity trends from 1980 to 2020

For countries with data for three or more waves of the IVS, trends in the prevalence of the four religiosity categories were estimated at country-level as follows:

  1. Values for single missing waves between two other waves were estimated using the geometric average for the two waves with data
  2. For countries in the Returned West or Orthodox East, the average change in prevalence due to the breakup of the Soviet Union was estimated using the average for those countries with data for the first wave in the 1980s and the second wave in the 1990s. This average jump was used to estimate values for the first or second wave for countries where one of these was missing.
  3. For countries where one or more early waves or one or more late waves were missing, prevalences were projected forwards or backwards using the median annual rate of change calculated at culture zone level for countries without missing waves.
  4. Population-weighted average trends were then calculated for each culture zone with the following two exceptions. For the Returned West and Orthodox East, prevalences were assumed constant prior to 1991. For Islamic East countries, flat trends were assumed from 1980 to earliest available data, as Turkey is the only Islamic country with data prior to 2000, and its trends are probably not representative.

For countries with data from only one or two waves, forward and back projections to 1981 and 2018 were made using the average trends calculated in step 4 above for each culture zone.

For projections from the Wave 7 survey year to 2020, a conservative approach was taken to avoid making extreme projections based on substantial differences between Wave 6 and Wave 7 estimates which may reflect variations in survey sampling or procedures rather than real change. For each country, the recent trend was estimated using data from survey waves in the period 2000-2020, with each earlier wave being given 15% less weight in the regression than the subsequent wave.  Average annual rates of change (aar) were also calculate from the Wave 6 and Wave 7 average prevalence estimates for each culture zone.

Where the regression aar were more extreme than the culture zone average aar, an average of the two was used for projection to 2020. Where the regression aar and the culture zone aar were of opposite signs, the regression aar was halved before use for projection. To be even more conservative, if the last Wave for a country was more than a year earlier than 2020, the rate of change from the survey year to 2020 was assumed to be aar1.5.

Finally, annual estimates for all years from 1980 to 2020 were prepared as follows:

  • Values prior to 1981 (the actual or projected first wave values) were assumed to be constant at the first wave values
  • Values beyond 2020 were also assumed to be constant at the 2020 value
  • Annual values between waves were estimated by linear interpolation
  • Annual values from 1980 to 2020 were smoothed using a 5-year moving average.

b. Imputation of religiosity for countries not included in the WVS/EVS.

Religiosity categories were imputed for 12 countries using data from Win/Gallup surveys for years 2012, 2015 and 2017 [7-9] which includes a question “Are you a religious person?” with the same response categories as the WVS/EVS question. These countries were Afghanistan, Cameroon, the Democratic Republic of the Congo, Cuba, Fiji, Kenya, Mongolia, Panama, Papua New Guinea, North Korea and South Sudan. Religiosity category prevalences for Israel were imputed from a Pew Research Centre survey which also included similar questions on religiosity [10].

For the remaining 63 mostly small countries, religiosity was imputed using culture-zone-specific regressions of the IVS religiosity prevalences against Pew Research Centre country-specific estimates for the year 2020 of religious affiliation distributions for 8 religious categories, including “other” and “none” [11].

c. Definitions of culture zones used to group countries

I am using the 10 culture zones defined by Welzel [4], with one modification. Because Australia’s and New Zealand’s culture values are much closer to the countries of the Reformed West than to those of the USA and Canada, I have included Australia and New Zealand in the Reformed West and renamed the New West as North America. The culture zones are defined as follows:

Reformed West — Western European societies strongly affected by the Reformation: Denmark, Finland, France, Germany, Iceland, Netherlands, Norway, Sweden, Switzerland, United Kingdom, plus Australia and New Zealand;
North America — USA and Canada;
Old West — Mostly Catholic parts of Western Europe being core parts of the
Roman Empire: Austria, Belgium, Cyprus, Greece, Ireland, Israel, Italy, Luxembrg, Malta, Portugal, Spain;
Returned West — Catholic and Protestant parts of post-communist Europe returning
to the EU: Croatia, Czechia, Estonia, Hungary, Latvia, Lithuania, Poland, Slovakia, Slovenia;
Orthodox East — Christian Orthodox or Islamic parts of the post-communist world,
mostly parts of former USSR;
Indic East — Parts of South and South East Asia under the historic influence
of Indian culture: Bhutan, Cambodia, India, Indonesia, Laos, Malaysia, Maldives, Myanmar, Nepal, Pakistan, Philippines, Singapore, Sri Lanka, Thailand, Timor-Leste;
Islamic East — Regions of the Islamic world that have been parts of the Arab/Caliphate,
Persian and Ottoman empires;
Sinic East — Parts of East Asia under the historic influence of Chinese culture: China, Hong Kong, Japan, Macau, Mongolia, North Korea, South Korea, Taiwan, Vietnam;
Latin America — Central and South America and the Caribbean;
Sub-Saharan Africa — African countries south of the Sahara
Oceania — Melanesian and Polynesian countries: Fiji, Kiribati, Nauru, Palau, Papua New Guinea, Samoa, Solomon Islands, Tonga and Vanuatu.


  1. EVS (2021): EVS Trend File 1981-2017. GESIS Data Archive, Cologne. ZA7503 Data file Version 2.0.0,
  2. EVS/WVS (2021). European Values Study and World Values Survey: Joint EVS/WVS 2017-2021 Dataset (Joint EVS/WVS). JD Systems Institute & WVSA. Dataset Version 1.1.0, doi:10.14281/18241.14.
  3. Haerpfer, C., Inglehart, R., Moreno, A., Welzel, C., Kizilova, K., Diez-Medrano J., M. Lagos, P. Norris, E. Ponarin & B. Puranen et al. (eds.). 2021. World Values Survey Time-Series (1981-2020) Cross-National Data-Set. Madrid, Spain  &  Vienna,  Austria:  JD  Systems  Institute  &  WVSA Secretariat. Data File Version 2.0.0, doi:10.14281/18241.15.
  4. Welzel C. Freedom Rising. Human Empowerment and the. Quest for Emancipation. 2013. Cambridge: Cambridge University Press.
  5. Pew Research Center, Oct 29, 2018. Eastern and Western Europeans Differ on Importance of Religion, Views of Minorities, and Key Social Issues.
  6. Arab TA, Maleki A. Iran’s secular shift: new survey reveals huge changes in religious beliefs. The Conversation, Sept 10 2020.
  7. WIN Gallup International. Global Index of Religiosity And Atheism – 2012.  WIN-Gallup International. 27 July 2012.
  8. WIN Gallup International. Losing Our Religion: Two Thirds of People Still Claim to Be Religious. WIN/Gallup International. 13 April 2015.
  9. WIN Gallup International. Religion Prevails in the World. WIN/Gallup International. 10 April 2017.
  10. Pew Research Center, March 8 2018. Israel’s Religiously Divided Society.
  11. Pew Research Center, April 2 2015. Religious Composition by Country, 2010-2050.
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