Between 2010 and 2020, the number of individuals identifying as religiously unaffiliated surged by 270 million, bringing the total to 1.9 billion. This demographic now constitutes 24.2% of the world’s population, according to a comprehensive analysis conducted by the Pew Research Center. The study, utilizing data from over 2,700 censuses and surveys across 201 countries and territories—representing nearly all of the global population—highlights the notable growth in people identifying as atheists, agnostics, or simply as having “no religion.”
Defining the ‘Nones’
The term “nones” refers to a diverse group of individuals within the religiously unaffiliated category. This group includes those who self-identify as atheist, agnostic, or “nothing in particular.” According to the latest data, 17% of nones identify as atheist, 20% as agnostic, while 63% describe their religious affiliation as “nothing in particular.” As of 2020, the “nones” have emerged as the third-largest religious cohort worldwide, following Christians, who number approximately 2.3 billion, and Muslims, estimated at 2.0 billion. The rise of the unaffiliated population has been accompanied by a corresponding decline in the percentage of individuals who identify with religious traditions, particularly Christianity.
Trends in Religious Disaffiliation
The increase in the unaffiliated population is largely attributed to attrition from religious institutions. Since 2010, the proportion of individuals with a religious affiliation has dropped by nearly one percentage point, while the number of those with no religious affiliation has risen by a similar margin. Despite this trend, many nones do not reject the idea of spirituality; approximately 29% express belief in a higher power.
Demographics Behind the Growth
The growth of the unaffiliated demographic is particularly striking given their relative demographic disadvantages. Notably, the unaffiliated community has the lowest percentage of children under 15 years old globally. However, the sharp increase in their numbers can primarily be attributed to religious switching, wherein individuals raised without a particular faith have moved away from various religions. Recent data indicates that for every person who joins a religion from an unaffiliated background, roughly 3.2 leave established faiths.
Country-Level Shifts in Religious Affiliation
Between 2010 and 2020, the unaffiliated segment saw significant gains in 35 countries. Particularly notable increases occurred in the United States, where the unaffiliated population grew by 13 percentage points, followed by Uruguay and Chile with even larger increases. On the other hand, Christianity experienced substantial declines, with large demographic shifts noted in countries like Australia and the United States, signaling changes in religious majorities.
Geographic Concentration of Non-Religious Groups
China holds the largest population of unaffiliated individuals, totaling 1.3 billion or about 90% of its population. The United States ranks second with approximately 101 million nones, marking a significant increase from a decade ago. Japan follows closely with 73 million unaffiliated individuals. Collectively, these three nations represent a substantial portion of the global religiously unaffiliated population.
Global Context and Comparative Analysis
The overall global landscape has also been marked by significant changes among religious groups. While Muslims experienced growth in their global share, Christians faced demographic declines. The religiously unaffiliated grew notably not due to higher birth rates, but primarily through disaffiliation from religious institutions. By 2020, nearly one in four people worldwide identified as non-religious, underscoring a transformative shift in global belief systems and raising questions about the future landscape of religion worldwide.
