This isn't an especially newsworthy finding, I wouldn't think, given all the anecdotal evidence out there, but AFP thought it was because the study revealed that even atheists held this view about their fellow atheists:
An unusual social study has revealed that atheists are more easily suspected of vile deeds than Christians, Muslims, Hindus or Buddhists -- strikingly, even by fellow atheists, researchers said Monday.There are more details at the link. I'm not sure, though, why Gervais is surprised by this result. How many of the mass murderers in the U.S. were either atheists or Islamic terrorists? I would venture to guess that the number is close to 100%. Moreover, those who were not atheists or Muslims I would venture to guess are only nominal theists who at best hold very tenuous, inchoate views about God.
This suggests that in an increasingly secular world, many -- including some atheists -- still hold the view that people will do bad things unless they fear punishment from all-seeing gods.
The results of the study "show that across the world, religious belief is intuitively viewed as a necessary safeguard against the temptations of grossly immoral conduct," an international team wrote in the journal Nature Human Behaviour. And it revealed that "atheists are broadly perceived as potentially morally depraved and dangerous."
Participants were given a description of a fictional evildoer who tortured animals as a child, then grows up to become a teacher who murders and mutilates five homeless people.
Half of the group were asked how likely it was that the perpetrator was a religious believer, and the other half how likely that he was an atheist.
The team found that people were about twice as likely to assume that the serial killer was an atheist.
"It is striking that even atheists appear to hold the same intuitive anti-atheist bias," study co-author Will Gervais, a psychology professor at the University of Kentucky in Lexington, told AFP.
There are two different reasons, in my opinion, why perpetrators of mass evil, at least in this country, are likely to be either atheists or Muslims. In the latter case it's because the perpetrator is convinced, not unreasonably, that the religion to which he is devoted actually encourages the murders of infidels, apostates, Jews, and those who dishonor the family name.
In the former case the reason is not so much that the perpetrator lacks a belief in Divine punishment, although that may be part of it, but rather that an atheist perpetrator has no good reason for thinking that any deed he might perform is morally evil in the first place.
If atheism is true then we're all just highly evolved animals, and there's no moral evil among animals. When a cat kills a mouse, even if the killing is simply gratuitous and unrelated to acquiring food, it's not doing evil. It's just doing what cats do. So it is with human beings. When one man slays another he's just doing what humans have been doing to each other ever since Cain and Abel.
Morality, on atheism, is simply something humans have devised to help them live together in society and avoid constant conflict, but if someone violates society's moral conventions they're not doing something wrong in any ultimately meaningful sense. They're just doing something that other people don't like.
When we condemn a mass killer all we're doing is expressing our disapproval of what the killer did, sort of like when fans at a baseball game boo the umpire, but the umpire who makes a bad call hasn't done anything immoral and neither has the killer. For the killer's act to be immoral he must be accountable to a higher law and a higher judge than merely the laws and judges of human society.
Thus, the presumption that someone who does evil is likely to be an atheist is a perfectly rational surmise, and the study simply shows that reflective atheists, just like most others, recognize the fact.
A theist, if he's genuinely committed to his belief, knows that if he does a horrible deed he's doing something deeply and genuinely wrong and is betraying both the faith he professes to hold and the God he professes to love. When an atheist does something horrible he has no reason to think he's doing anything wrong or betraying anything at all.
Between the two, then, who is more likely to wreak evil upon others?