Globally, 1 in 10 adults under 55 have left their childhood religion

As of 2020, people who identify with a religion make up about 76% of the world’s population, according to a new Pew Research Center study on global religious change. This is down by about 1 percentage point from 2010. The decline is largely due to people shedding their religious identity after having been raised in a religion.

Globally, among adults under 55 who were raised in a religion, an estimated 10% have since switched, either to a different religion or to identifying with no religion.

How we did this

This analysis of religious “switching” is based on Pew Research Center’s June 2025 report “How the Global Religious Landscape Changed from 2010 to 2020.” We drew on surveys from 117 countries and territories: 96 Center surveys conducted between 2009 and 2024, 20 International Social Survey Programme (ISSP) surveys conducted in 2008 or 2018, and the 2018 Chinese General Social Survey (CGSS).

We calculated rates of religious switching using responses to two questions that have been consistently included in our surveys and ISSP surveys. In our surveys, they are, “What is your religion, if any?” and “Thinking about when you were a child, in what religion were you raised?” In ISSP surveys, they are, “What is your religion” and “What religion, if any, were you raised in?”

In China, we took a slightly different approach. The 2018 CGSS does not include the same measure of childhood religion. Instead, we used responses to the question, “What was your mother’s religion when you were 14?” as a proxy. Read Appendix A for a list of countries and source information.

Together, these 117 surveys cover countries that encompass 92% of the global population ages 18 to 54 in 2010, including almost all Hindus, 98% of religiously unaffiliated people and 93% of Christians. Coverage is also high for Buddhists (85%) and Muslims (82%).

We limited the analysis to adults under 55 to focus on switching that has happened in recent decades. Among survey respondents who have changed religion, we don’t have data on the age at which they switched. Religious changes can occur at any age, but previous studies have found that religious switching is more common among younger adults than among older adults. Therefore, switches by adults 55 and older probably occurred longer ago, on average, than switches by adults under 55.

The surveys we analyze do not allow us to isolate religious switching that took place in a specific year. Rather, they provide an overview of switching patterns in recent decades.

In this analysis, we focus on Christians, Muslims, Hindus, Buddhists and the religiously unaffiliated. Results for Jews and members of other religions are not shown. We conducted sensitivity tests to ensure the robustness of our switching estimates (rates of leaving vs. joining) and found that the rates of joining Judaism and the “other religions” category are unstable because of their small sample size in most surveys. Read the June report’s Methodology for more details.

What is religious ‘switching’?

Religious switching refers to a change between the religious group in which a person says they were raised (during their childhood) and their religious identity now (in adulthood).

We use the term “switching” rather than “conversion” because many people who switch identities leave religion to become religiously unaffiliated.

We count changes between seven large religious categories (such as from Buddhist to Christian, or from Hindu to religiously unaffiliated) but not switching within each category (such as from Catholic to Protestant).

To understand the global patterns of “switching” into and out of each religious category, we analyzed surveys from 117 countries and territories that cover 92% of the 2010 global population. Although religious switching may occur at any age, it is more common to experience as a young adult. Therefore, this analysis focuses on survey respondents ages 18 to 54 to look at more recent global switching patterns.

We discuss religious switching for Christians, Muslims, Buddhists, Hindus and the religiously unaffiliated. We also analyzed results for Jews and members of other religions, but they are not shown separately in this post because of their small sample sizes.

The “Religiously unaffiliated” category includes people who say they are atheist, agnostic or “nothing in particular” in response to a Pew Research Center survey question about religious identity. It also includes people who choose a “No religion” or “None” option in other surveys and national censuses.

Below, we explore the following key questions about religious switching around the world:

• How common is it for people to stay in or leave their childhood religion?
• Which religious category do people most commonly switch into?
• Which religious category has grown or shrunk the most from religious switching?
• What types of countries have the most religious switching?

How common is it for people to stay in or leave their childhood religion?

Globally, 91% of adults ages 18 to 54 say they still belong to the religion – or nonreligion – in which they were raised. This is sometimes referred to as “retention.” However, the share of people who retain their childhood religious identity in adulthood varies across religious categories.

Hindus and Muslims have the highest retention rates at 99% each. Just 1% of 18- to 54-year-olds who were raised Hindu or Muslim have switched out of the groups.

Among adults who were raised religiously unaffiliated, 93% still do not identify with any religion.

Christians – the world’s largest religious group – are less likely to retain their religion. About 83% of adults raised Christian are still Christian.

Buddhists have the lowest retention rates among the religious categories we studied. Fewer than eight-in-ten adults who were brought up as Buddhists (78%) have retained their religion.

Which religious category do people most commonly switch into?

Most religious switching around the world is disaffiliation – people leaving their childhood religion and no longer identifying with any religion.

Buddhists and Christians are the religious groups with the highest shares of people becoming religiously unaffiliated. For example, 19% of adults who were raised Buddhist no longer identify with any religion. Another 3% now identify with a different religion.

In contrast, it’s more common for people who were raised Hindu and Muslim to join a different religion than to identify with no religion.

Among adults who were raised without a religion, 7% of them have adopted a religion since childhood.

Which religious category has grown or shrunk the most from religious switching?

How switching affects the size of each religious group depends not only on retention, but also on how many people have joined the group.

Christians experienced the greatest overall losses due to religious switching. For every 100 adults ages 18 to 54 who were raised Christian, 17.1 left and 5.5 joined, resulting in a net loss of 11.6 people.

Buddhists had the highest rate of people leaving the religion (22.1 per 100 people raised Buddhist) among the groups we studied. But their rate of people joining is also relatively high (12.3). Taken together, Buddhists had the second-largest net loss from religious switching: 9.8 people for every 100 raised Buddhist.

The religiously unaffiliated had a net gain of 16.7 people for every 100 who were raised with no religion. That came from having the highest rate of people joining (24.2) and a moderate rate of people leaving (7.5).

Switching had little effect on the Muslim and Hindu populations because the modest rates of switching into and out of the religions roughly balanced out.

Religious switching fueled declines in the Christian and Buddhist populations between 2010 and 2020. The Christian share of the global population fell by 1.8 percentage points, and the Buddhist share dropped by 0.8 points.

What types of countries have the most religious switching?

Around the world, religious switching is more common in places that score higher on the United Nations’ Human Development Index (HDI), which measures average life expectancy, education levels and per capita income. In 51 places with HDI scores of 0.8 or greater – which the UN considers a “high” score – a median of 18% of 18- to 54-year-olds have switched religions.

In countries with low HDI scores, on the other hand, changing religions is rare. In the 16 countries with HDI scores below 0.55, which the UN considers a “low” score, a median of 3% of 18- to 54-year-olds have left their childhood religion.

However, economic development does not perfectly align with rates of religious switching, as several countries across the range of HDI scores have low rates of switching. This includes many Muslim-majority countries and Buddhist-majority Thailand and Cambodia.

In some countries with low rates of religious switching, laws restrict citizens from leaving their religion. For example, Algeria, Brunei, Egypt and Malaysia have laws penalizing citizens for leaving Islam for a different religion. Many states in India also have anti-conversion laws.