Why (We Think) Atheists are More Likely to be Serial Killers

Page of a dictionary, with focus on the word 'atheism.' (Getty Images)
UConn anthropologist Dimitris Xygalatas and colleagues conducted research that showed global moral prejudice against people who do not believe in a god or gods. (Getty Images)

UConn anthropologist Dmitris Xygalatas and colleagues this week published research that showed global moral prejudice against atheists. They interviewed Christians, Buddhists, Muslims, Hindus, and secular people from several different societies and found that no matter which culture they came from, they were biased against people who did not believe in a god or gods. The study was published online in the Aug. 7 issue of  Nature Human Behavior

Here, we delve into the reasons for religion, prejudice, and why even atheists are often prejudiced against other unbelievers.

Q. Your research found that people the world over believed a serial killer was more likely to be an atheist than a believer in god(s). Why was this surprising, and what does it mean?

A. Although this result was certainly no surprise to us (it was the original hypothesis of the study), it is certainly puzzling. As an anthropologist, I have often heard people argue that without religion there is no morality. And last year, during the presidential campaign, Ted Cruz argued that people of all faiths have the constitutional right to run for the presidency, but atheists are not fit for the job. However, data from the Federal Bureau of Prisons suggest that atheists are far less likely to commit crimes than religious people, and globally the least religious countries have the lowest crime rates. This is of course correlational evidence: it does not mean that being an atheist leads to committing fewer crimes. But the intuition that our study reveals, i.e. that atheists are immoral, is definitely not supported by reality.

Q. As part of the study, people were told a story about a man who tortured animals as a child and moved on to other violent acts as he matured, culminating in murdering five homeless people. Then the people were asked: is this man more likely to be a teacher? Or a teacher who does not believe in god(s)? Those two answers are logically inconsistent why did you ask that question in that way?

A. This question was designed to exploit the “conjunction fallacy,” a common logical error that people make when asked to estimate the probability of some specific condition versus a more general one. This is also known as the “Linda problem”, and it is typically presented in the following way: “Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations. Which is more probable? a) Linda is a bank teller, or b) Linda is a bank teller and is active in the feminist movement.

The correct answer is of course a), because the number of feminist bank tellers can never be higher than the number of bank tellers. But most people give the wrong answer to this problem, because the person’s description sounds more representative of option b). Our study simply looked at how often people committed this fallacy when the person in the story was described as atheist versus religious. This allowed us to examine people’s intuitions, rather than more reflective, politically correct answers.

Q. What is atheism? Is it a universally understood concept, or do people in various cultures interpret atheism differently?

A. In a strict sense, an atheist is someone who does not believe in the existence of any deity or supernatural forces. However, there are also many people who describe themselves as “agnostic”, which means that they acknowledge the possibility of a supernatural reality, although that reality might be unknowable to us. In addition, there are many people who describe themselves as being non-religious but spiritual in other ways. Our study described the protagonist of the story as “not believing in god.” I expect that if he had been described specifically as an “atheist,” the bias would have been even more pronounced.

Q. Many people in Europe, and some in the U.S. and other places, define themselves as secular with regard to religion. Is that the same as claiming to be an atheist?

A. If we look at some of the world’s most secular countries, let’s say the Czech Republic or Denmark, we find that there are quite a few atheists, but also a very large percentage of the population who reject organized religion but still describe themselves as “spiritual,” for example they may believe in supernatural forces like karma.

Q. The study showed that even self-avowed atheists believed the serial killer more likely to not believe in god(s). Who were these atheists which cultures were they from, and did they actually define themselves as atheists?

A. This is what philosopher Daniel Dennett has called “belief in belief.” A lot of the people who are not religious believe that religiosity has positive benefits and should be fostered even if it is fallacious. This is what we see in this study. Non-religious participants in all of the countries we surveyed, even the most secular ones, exhibited the same bias against atheists, although to a lesser degree than religious participants.

Q. How does this change how we understand morality?

A. Scientific evidence suggests that humans (and even their primate cousins) have innate moral predispositions, and religion is a reflection rather than the cause of these predispositions. However, our results show that people around the world still carry deeply-ingrained biases when judging the moral attributes of others.

Q. Does this tell us anything about the purpose of religion in society?

A. Religion has been so successful in the course of human history partly because it functions as a public signal of conformity to group norms, and that is because it involves arbitrary rather than functional rules and behaviors. For example, hunting, fishing, or trading like everyone else is the logical thing to do and offers directly observable benefits (food on the table and money in the bank). But going to church, fasting, or memorizing the Bible are costly signals of commitment to the norms of the community. Reliance on such signals has been crucial for the formation and maintenance of the first large-scale societies, in the absence of reliable secular institutions, and this evolutionary heritage is still with us today.

The research was funded by grants from the John Templeton Foundation (48275) and the John Templeton World Charity Foundation (0077), as well as the Royal Society of New Zealand, the Interacting Minds Centre at Aarhus University and the Netherlands Organization for Scientific Research.

Xygalatas collaborated on the study with researchers at the University of Kentucky, led by William M. Gervais, and at several other institutions in Europe, Asia, and the Middle East.