In the United States, one of the most consequential cultural changes of our time may be the swift and seemingly accelerating decline of religious commitment.

Historically, Americans have recorded relatively high levels of worship-service attendance and belief in God, as compared with their peers in advanced industrial societies such as Europe or Japan. The U.S. example seemed to show that faith could survive in an environment dominated by science and technology.

A forthcoming book by University of Michigan political scientist Ronald F. Inglehart, however, suggests that the United States is now rapidly catching up with the trend toward secularization elsewhere.

When asked to express the importance of God in their lives on a scale of 1 to 10, with 1 being “not at all important,” and 10 being “very important,” Americans rated Him at an average of 4.6 in 2017 — down from 8.2 in just over a decade, according to an excerpt of Inglehart’s book, “Religion’s Sudden Decline,” in the current issue of Foreign Affairs.

A major source of this country’s relative social and political conservatism is, essentially, disappearing, with potentially far-reaching implications for everything from criminal justice to education to foreign policy. Increasingly, the two political parties are not characterized by their respective predominant religious groups, but by whether their adherents belong to any religion at all. Thirty-eight percent of Democrats say they regularly attend services; for Republicans, the figure is 54 percent.

The U.S. importance-of-God score started higher than others and had more room to fall. Still, Inglehart’s finding reinforces those the Pew Research Center published last October, showing that the share of Americans claiming “none” as their religious affiliation had grown from 16 percent to 26 percent since 2007. Fewer than half of Americans now attend services regularly — with only 35 percent of millennials going at least once a month.

Why the dramatic change in only a decade? Inglehart portrays the U.S. shift as part of a global trend also perceptible in 43 of the 49 countries (containing 60 percent of the world’s population) that he studied.

That trend, in turn, reflects an even more sweeping one: Social and economic development renders human survival less precarious, human suffering less dramatic — and human beings less needful of existential comfort or guidance from age-old traditions.

Inglehart notes that religions generally revolve around beliefs, and rules, about sex, gender roles and family that are “closely linked to the imperative of maintaining high birthrates.” In modern societies that have mostly conquered infant mortality — while extending life expectancy — that imperative loses relevance.

The decline of traditional religion is thus an indirect, but foreseeable, result of demographic transition and may spread to less developed countries as they modernize.

Inglehart’s argument fits some cases better than others. Religious commitment has increased since 2007 in India, according to his data. During this time, India was one of the fastest-growing economies in the world; its infant mortality rate declined by nearly half.

Inglehart ascribes this anomaly to the ruling Bharatiya Janata Party’s promotion of Hinduism-based nationalism — and Indian Muslims’ counter-assertion — but an exception that encompasses 17.5 percent of the world’s population is large indeed.

Meanwhile, his data suggest that religious feeling also has been waning in China, where 18 percent of the world lives. There, too, government policy is a confounding variable: China’s systematic repression of Islam, Tibetan Buddhism, Christianity and Falun Gong probably results in less adherence to religious faith and more reluctance to admit it in surveys. (Inglehart acknowledged this in an email reply to my question.)

Inglehart’s hypothesis works best for countries, such as the United States, where government does not manipulate choices on religious affiliation.

A possible additional influence is social media — whose arrival as a mass cultural phenomenon coincides with the onset of religion’s decline in 2007.

Religious institutions make use of social media themselves, to be sure. But social media enables people to establish communities, make friends and meet romantic partners without the aid of a church or other religious gathering place. It offers near-infinite distracting alternatives to religious study. It enables negative information about organized religion — e.g., the pedophilia scandal in the Catholic Church — to spread in ways religious authorities cannot control or counter.

Inglehart suggests that traditional religion could have a comeback if the pandemic and associated hardships lead people to rediscover solace from God. Spirituality — the search for meaning — is a basic human need, which Americans will continue to address, either within established God-centered religions or otherwise.

For the time being, however, the intense moral passion our ancestors in America once channeled into disputes among existing religious creeds, or the establishment of new ones, is finding a different outlet: politics.