Well, I'm not sure about this. And I think there are a couple of ways to explain such findings. I think if you were to take a group of say, 10 churches, and then that many atheists you would find more of the above with the atheists. But, I could be wrong.
Anyways, I could see how this would be so. Today there seems to be two Christian groups: 1. Older 2. Younger. This is debatable probably, but go along with it...
It is not uncommon for the younger Christian's to rebel. Some Christian family's are very conservative, and it doesn't surprise me that a young person would want to break free and rebel. Now that doesn't apply to rapes and murders, usually younger people don't do that sort of thing. I think for these you will find that these people were *once* Christians and somehow God or the church made them angry and they took this anger out on others.
As for "niceness" yea I don't think Christian's would be any "nicer" than an atheist. You'll meet very nice Christian's and you'll meet very nice atheists and of course you'll meet the opposite of niceness with both. It all evens out.
Denmark and Sweden...two highly industrialized, largely homogeneous, Western European countries with the luxury to allocate most of their government expenditures to social programs.
Sure, the US may be richer, faster, stronger, smarter, taller, more handsome, all that--but our disparities are what skew our stats. The concentration of wealth and access to health care and education lie in the hands of the few. The averages may look good, but the standard deviation is where the truth lies.
As a firm Athiest I tried to get through that article and was bored stiff before the first paragraph was over. I can say that all Athiest I have meet are not mean or violent people. They just dont believe the book that was written 1600 years ago about a guy that lived 400 years earlier.