Atheism is on the rise and religious belief in decline
There is considerable interest in the prevalence of atheism, particularly from Americans, and a variety of quite different statistics are quoted, and have been written about in various media. Substantial difference in prevalence of atheism can result from differences in question wording and response categories, survey methods and even in definitions of atheism. This also makes it difficult to compare levels of atheism across countries or over time.
To obtain better and more comparable statistics, I have analysed data from the World Values Survey and European Values Study (the integrated data are available here). The WVS and EVS surveys have interviewed over 630,000 people in 110 countries using a standard set of questions. The surveys have been carried out in seven waves over the period 1981 to 2020. They include a direct question on whether you believe in God (Yes/No/Don’t know), but also “Are you a religious person” (Religious, Non-religious, Confirmed Atheist) and questions on frequency and type of religious practices, and on the importance in your life of religion and God. Of the 105 countries, 76 have data for years in range 2017–2020, and another 17 have data on or later than 2010.
Atheism and irreligion in 2020
I define atheism as the lack of a belief in God (or gods). A respondent is classified as an atheist if they respond “No” or “Don’t know” to the question “Do you believe in God” or state that they are a “Confirmed Atheist” in response to the question “Are you a religious person”. I don’t actually know what is meant by “Confirmed Atheist”, and much fewer people choose this label than say they do not believe in God.
I classify as “non-religious” the people who say they believe in God but rate the importance of God as 8–10 at the not-important end of a 10-point scale. The remaining “religious” people are classified as practicing or non-practicing depending on whether they attend religious services or pray to God outside religious services at least once a month.
The table below lists the 50 countries with the highest prevalence of irreligion (atheism + non-religious). The top 5 countries include three Asian countries (China, South Korea and Japan) and the top 10 include 5 countries from North or Central Europe. The top 15 countries also include Australia, New Zealand and Canada, all with prevalences of irreligion over 50%. The USA is in 31st place with 23% atheist and another 7% non-religious (in all 30% are irreligious).
The prevalence of atheism varies substantially across South America, from a high of 21% in Uruguay to less than 2% in some of the Caribbean islands.
The average prevalence of atheism in sub-Saharan Africa and the Islamic Middle East is around 2% and does not exceed 8% in any country. Atheism is severely stigmatized in most of these countries, and may have severe penalties. It is likely that the actual prevalence of atheism and irreligion is higher in Islamic countries than shown below, due to the risks and penalties associated with identifying as apostate or atheist. A recent internet-based anonymous survey for Iran found much higher levels of reported atheism (around 12%) and a lower level at 40% of Iranians who identify as Muslim.
Note that reported prevalence of atheism from other sources may be quite different to these results. Many of the reports of prevalence of atheism add the “non-religious” to the “confirmed atheist”, but the WVS/EVS data show that a majority of the non-religious believe in God but are estranged from institutional religion. Other reports use data on those who report “None” when asked their religion, but these also include many people who believe in God but have rejected institutional religion.
At the global level, I estimate that the prevalence of atheism is 28% in the year 2020, and irreligion 31%. Of the other 69%, 38% are practicing religious and 31% are non-practicing religious. Applying these percentages to the global population, I estimate that in 2020 there were a total of 2.2 billion atheists in the world, and 0.2 billion non-religious.
Global trends in atheism and religion
At global level, the proportion of people who are religious and practicing has barely changed over the last 40 years, nor has the prevalence of atheism. This conceals quite substantial changes in “Western” developed countries and in former Soviet-bloc countries, in opposing directions.
Western countries (Europe excluding the former Soviet-bloc countries, Australia, New Zealand, Canada and the USA) are characterised by a rapidly rising prevalence of atheism and corresponding decline in the proportion who are practicing religious. The former Soviet-bloc countries are characterised by a large drop in atheism prevalence and corresponding rise in the religious following the collapse of the Soviet Union around 1991. More recently, atheism is rising and practicing religious falling in the former Soviet-bloc countries who have joined the European Union, following a similar path to that taken by Western Europe.
Other former Soviet-bloc countries have experienced a 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 examined this more closely and found that for most people in these countries, being Christian (whether Catholic or Orthodox) or Muslim 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 non-practicing.
Latin America, the Islamic East and Sub-Saharan Africa are the “religious” regions characterised by very high prevalence of practicing and non-practicing religious people and very low prevalence of non-religious and atheists. India also has a low prevalence 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.
The survey data for the USA show 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% to 7% (see plot above). The prevalence of irreligion (atheists and non-religious) has increased in the USA by an estimated 22 percentage points over the last two decades, the fourth largest increase of any country included in this analysis. The largest increase occurred in neighbouring Canada with a 37% increase since year 2000. Apart from two Asian countries (South Korea and Singapore), 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.
The prevalence of atheists and the non-religious in Western countries is generally higher in younger people than older people. I have examined these age patterns in the USA and compared it with eight other high-income countries where the prevalence of irreligion exceeds 50% (Australia, Denmark, Finland, France, Netherlands, Norway, Sweden and the United Kingdom).
Although the prevalence of irreligion is lower in all age groups in the USA compared to the European countries, it is rising rapidly in all age groups under 60 years and will likely catch up to Europe soon. Trends are much smaller in Europe as much of the growth in irreligion occurred decades earlier, whereas it has really only started to increase substantially in the USA in the last decade. Irreligion in the youngest US age group (18–24 years) already exceeded 50% in 2018. As this cohort ages, and newer young cohorts likely have even higher levels of irreligion, it is very likely that over the next few decades the USA will reach similar levels of atheism as those found in Europe, Australia, Canada and New Zealand.