The percentage of Americans who believe in God is at an all-time low, study suggests

However, there was one anomaly in the findings

Millennials are the group least likely to believe in God (ANDREW CABALLERO-REYNOLDS/AFP/Getty Images)

The percentage of Americans who believe in God or pray is at an all-time low, a study has found.

Millennials could also be the most secular generation in American history, the team from San Diego State University discovered.

The research analysed data from 58,893 respondents to the General Social Survey, a nationally representative survey of US adults, conducted between 1972 and 2014.

It found that nearly twice as many Americans in 2014 said they did not believe in God as in 1980 and that five times as many in 2014 said they never prayed.

In addition, Americans in 2014 were less likely to engage in religious practices such as attending religious services and believing the Bible is divinely inspired.

In 2014, people were also less likely to identify as religious than in 1980.

The biggest declines in religious affiliation were among 18-to 29-year-olds.

“Most previous studies concluded that fewer Americans were publicly affiliating with a religion, but that Americans were just as religious in private ways. That’s no longer the case, especially in the last few years,” said study lead, psychology professor Dr Jean Twenge.

“The large declines in religious practice among young adults are also further evidence that Millennials are the least religious generation in memory, and possibly in American history."

Dr Twenge is sceptical that there has been an increase in spirituality to compensate for the decline of religion in America.

Instead, she suggests that America is becoming more secular.

However, there was one aspect of the study which ran contrary to the rest of the findings.

A small rise was observed in the number of people who believed in an afterlife.

"It was interesting that fewer people participated in religion or prayed but more believed in an afterlife,” Dr Twenge said.

“It might be part of a growing entitlement mentality – thinking you can get something for nothing.”