Religious identity is shrinking across much of the world, typically beginning when younger generations stop attending worship services, according to new research that traces how disaffiliation with faith unfolds over time.
A Pew Research Center study, published in the journal Nature Communications alongside an academic paper by international scholars, found that between 2010 and 2020, the share of people who identify with a religion fell by at least five percentage points in 35 countries. In some nations, the drop was far steeper — 17 points in Australia and Chile, 16 in Uruguay and 13 in the United States.
The research proposes that these shifts occur in stages of what scholars call a “secular transition.” Using surveys from 111 countries and territories, they describe a recurring three-step sequence in which religion declines across generations: first in worship service participation, then in personal importance, and finally in belonging. They call this the Participation-Importance-Belonging (P-I-B) sequence.
In the early stage, younger adults attend services less often than older adults, but most still say faith is important and continue to identify with their religion. Many African countries fit this pattern today. In Senegal, for example, 78% of older adults attend worship weekly, compared with 64% of younger adults. Yet both groups report strong belief and nearly universal Muslim identity.
The medium stage is marked by generational gaps across all three steps: attendance, importance and belonging. In the United States and several countries in the Americas and Asia, younger adults not only go to church less frequently, but also place less emphasis on religion in daily life and are more likely to describe themselves as having no religious affiliation.
The late stage comes when attendance and the importance of faith are already low across age groups, leaving religious belonging as the main dividing line. Many European countries fall into this category. In Denmark, for instance, 79% of older adults still identify with a religion, but the share among younger adults is 26 points lower, even though worship attendance is low among both groups.
The authors note that countries dominated by Christianity or Buddhism are most often in the medium or late stages, while Muslim-majority countries and Hindu-majority India remain in the early stage. Whether they follow the same trajectory is uncertain.
There are also exceptions. In post-communist Eastern Europe, Orthodox- and Muslim-majority nations such as Russia, Azerbaijan, Moldova and Georgia diverge from the pattern, reflecting decades of religious suppression followed by nationalist religious revivals. Israel, the world’s only Jewish-majority nation, also shows unique trends: younger Israelis are as religious as older ones, largely due to high birth rates among Orthodox and ultra-Orthodox families.
The researchers emphasize that while the secular transition appears in many countries, it is not uniform or inevitable. The timing of when societies begin the process — and whether they continue through all three stages — varies widely.
The study was authored by Jörg Stolz and Jean-Philippe Antonietti of the University of Lausanne, Nan Dirk de Graaf of the University of Oxford, and Pew Research Center’s Conrad Hackett. It draws from Pew’s global surveys and offers one of the most detailed analyses to date of how and why religious affiliation is changing across generations.
