The decline in the share of Christians in the US population appeared to have stopped, according to a major new survey. This is notable because it seems to contradict the thesis that the decline of Christianity in Western countries is inevitable and irreversible.

The survey, from the Pew Research Center, says that the proportion of Americans identifying as Christians has stabilised at around 62pc. The figure was 78pc in 2007 but has stopped falling over the last five years.

The study, involving more than 100,000 respondents, finds that self-declared Protestants make up 40pc of the U.S. adult population, while Catholics account for 19pc. Of course, saying you belong to a particular religious group does not make you actually practice that religion.

Meanwhile, the religiously unaffiliated, often referred to as “nones” (atheists, agnostics, or those who identify as “nothing in particular”), now constitute 29pc of the population. After a long period of growth, this group has also stabilised in recent years.

Other measures of religious practice indicate stability. The percentage of Americans who pray daily has remained between 44pc and 46pc since 2021, while regular religious service attendance (at least monthly) has held steady in the low 30s since 2020.

However, there are notable generational differences: younger adults (18-24) are significantly less religious than older adults (over 74). Only 46pc of the youngest adults identify as Christian, compared to 80pc of the oldest cohort. Additionally, 27pc of young adults pray daily, compared to 58pc of seniors, and just 25pc of younger adults attend religious services monthly, compared to 49pc of older adults.

Family size also varies by religious affiliation. Christians of the age group 40-59 have more children (2.2) than the religiously unaffiliated (1.8) and non-Christian religious groups (1.8).

These figures reflect self-identified Christian respondents, but the survey does not look at the number of children people have based on religious practice. Generally, fertility rates tend to be higher among those who attend religious services more frequently.

Demographer, Lynam Stone, has shown that Americans who attend religious services weekly or more, have about 2.2 children on average, compared with just 1.35 or so for those who never attend. A new paper from The Iona Institute examines the positive correlation between religious practice and larger families.

Women remain more religious than men, though the gender gap is narrowing, especially among younger generations. Among parents with under-18s at home, 42pc report engaging in religious activities such as prayer or scripture reading with their children.

Changing religious affiliation is common in the U.S., with 35pc of adults identifying with a different religion (or no religion) compared with in childhood.

Religious affiliation continues to correlate with political and social attitudes, according to the survey. Highly religious Americans are more likely to lean Republican and hold conservative views, while less religious individuals tend to align with the Democratic Party and support liberal policies.

Among ideological groups, liberals have experienced the most dramatic shift. In 2007, 62pc of self-identified liberals were Christian; by 2024, this number had dropped to 37pc. Conversely, the percentage of liberals with no religious affiliation rose from 27pc to 51pc, making religious “nones” the dominant group among liberals. Conservatives have also seen a decline in Christian affiliation but to a lesser extent, and a majority still identify as Christian.