from the internet-is-the-devil dept.
In 1990, about 8 percent of the US population had no religious preference but by 2010, this percentage had more than doubled to 18 percent. That's a difference of about 25 million people, all of whom have somehow lost their religion. Now MIT Technology Review reports that Allen Downey, a computer scientist at the Olin College of Engineering in Massachusetts, has analyzed the data in detail and says that the dramatic drop in religious affiliation is the result of several factors but about 25 percent of the drop is due to the rise of the Internet. Downey concludes that the increase in Internet use in the last two decades has caused a significant drop in religious affiliation: for moderate use (2 or more hours per week) the odds ratio is 0.82. For heavier use (7 or more hours per week) the odds ratio is 0.58.
What Downey has found is a correlation and any statistician will tell you that correlations do not imply causation. But that does not mean that it is impossible to draw conclusions from correlations, only that they must be properly guarded. "Correlation does provide evidence in favor of causation, especially when we can eliminate alternative explanations or have reason to believe that they are less likely," says Downey. It's straightforward to imagine how spending time on the Internet can lead to religious disaffiliation. "For people living in homogeneous communities, the Internet provides opportunities to find information about people of other religions (and none), and to interact with them personally," says Downey. "Conversely, it is harder (but not impossible) to imagine plausible reasons why disaffiliation might cause increased Internet use."
There is another possibility: that a third unidentified factor causes both increased Internet use and religious disaffiliation. But Downey discounts this possibility. "We have controlled for most of the obvious candidates, including income, education, socioeconomic status, and rural/urban environments. (PDF)" If this third factor exists, it must have specific characteristics. It would have to be something new that was increasing in prevalence during the 1990s and 2000s, just like the Internet. "It is hard to imagine what that factor might be."