In many parts of the world, secularism is on the rise, even in the United States where there has been a slow but steady drop in the number of people who affiliate themselves with a religion. Despite those changes, Benedict Carey at The New York Times reports that a new study reveals that an implicit bias against atheists, or those who don’t believe in any supernatural deity, remains, with most people judging atheists as less moral than religious people.

For the study, researchers surveyed 3,256 people in 13 countries from North America, Europe, Asia and the Middle East, collecting data on their age, religious affiliation and belief in god. Among brain teasers and random questions on a questionnaire, they included a query describing a man who tortured animals as a child and as an adult went on to abduct and kill five homeless people who are buried in his basement. One half of the subjects were asked: “Which is more probable? 1) The man is a teacher; or 2) The man is a teacher and does not believe in any gods.”

The other half were asked: “Which is more probable? 1) The man is a teacher; or 2) The man is a teacher and a religious believer.”

Carey reports that 60 percent of people given the option selected the man as an atheist. Only 30 percent of people given the option selected him as a religious believer.

Agence France-Presse reports that the bias was strongest in more religious countries including the United States, United Arab Emirates and India. New Zealand and Finland, both very secular nations, were the only countries in the study that did not show a bias against non-believers. The study appears in the journal Nature Human Behaviour.

“It is striking that even atheists appear to hold the same intuitive anti-atheist bias,” study co-author Will Gervais, psychology professor at the University of Kentucky, tells AFP. “I suspect that this stems from the prevalence of deeply entrenched pro-religious norms. Even in places that are currently quite overtly secular, people still seem to intuitively hold on to the belief that religion is a moral safeguard.”

But Ryan F. Mandelbaum at Gizmodo reports that atheists don’t exactly need to worry about villagers armed with implicit biases and pitchforks. In a commentary in Nature published along with the recent study, Arizona State University psychologists note that most relationships are not as cut and dry as the survey question presents. “Atheism is rarely the only piece of information known about interaction partners,” they write, “and it is possible that, when included with the social information that individuals collect naturally, atheism will be perceived as less indicative of immoral behavior.”

In the United States, at least, the social stigma around atheism may have caused people to choose to hide their non-belief, however. Daniel Cox at FiveThirtyEight reports that Gervais ​was also the lead author on a study published earlier this year which found that one in three people in the U.S. surveyed in the sample did not disclose their lack of belief. Using that data, the researchers suggest that number of people who identify as atheist in the U.S. might actually be as high as 20 percent to even 35 percent—a significant jump from the 3 percent to 11 percent who have self-identified as atheists on recent Pew and Gallup polls.