A US computer scientist has released a study claiming to have found out why so many Americans are abandoning their religious faith and says it's the internet's fault.

"Internet use decreases the chance of religious affiliation," reports Allen Downey, professor of computer science at Olin school of engineering.

Downey analyzed data from 20 years of polling by the National Opinion Research Center for its General Social Survey. He found that the number of people citing no religious belief increased from 8 to 18 per cent between 1990 and 2010, and argues the growth of internet use accounts for a large proportion of that.

Using Python scripts for analysis, Downey found that the biggest influence on religious belief was whether or not children had been raised in a particular faith. These numbers have dropped over the last 20 years, but not by much, and Downey says this drop only accounts for around a quarter of the increase in those eschewing religion.

Another important factor in the reduction of faith, according to the data, is having a college education. With more Americans in higher education these days, you'd expect to see a drop in religiosity. Downey, however, thinks the numbers are small enough to account for 5 per cent of those dropping out.

But internet use is another factor likely to reduce one's belief in a Supreme Being (or Beings, if you're a polytheist), he argues, noting that internet use rose from virtually nothing in 1990 to over three-quarters of the US populace 20 years later.

"Although a third unidentified factor could cause both disaffiliation and Internet use, we have controlled for most of the obvious candidates, including income, education, socioeconomic status, and rural/urban environments," Downey states.

"Also, in order to explain changes over time, this third factor would have to be new and rising in prevalence, like the Internet, during the 1990s and 2000s. It is hard to imagine what that factor might be."

Internet use is certainly causing religions many problems. Last year the head of the Mormon church in Europe, Hans Mattsson, caused an outcry when he reported that Mormon leaders refused to answer questions raised by greater knowledge of the founder of the church Joseph Smith.

"When members are using the internet, everything is there and they found out a lot of questions about the church history," Mattsson told The New York Times. Being a high leader in the church they passed those questions to me and I had to deal with them. We found out the church didn't give me any answers really."

This is not a new problem. The early Catholic church frowned upon translating the Bible into languages other than Latin, ostensibly because this was meddling with the word of god, but arguably also because it's easier to control a flock of parishioners when only the priest can translate life's instruction manual.

But, based on Downey's data, it may be a bit of a stretch to blame the loss of faith on the internet. The data shows, for example, that the bulk of lost believers come from the Protestant tradition, few Jews or Catholics have joined the ranks of the non-believers, and belief in other religions has actually risen.

In the opinion of this journalist, that data could well be Downey's missing factor. Here in the US, the last twenty years have seen a radical – and highly vocal – group of Protestants calling for the installation of a theocracy in the US, claiming evolution and Christianity are incompatible, and claiming the ills of the world are down to things like gay marriage or the ACLU.

Such tactics grab headlines, but are also driving moderates away from the pews. Given that the survey questionnaire asked for a "a religious preference," many of those answering may have chosen to keep their faith private rather than allying themselves with the radicals. ®