Religion, Morality and Crime

 [NOTE: This was originally written in October, 2014, and may not reflect the latest statistics.]

As an atheist I have come to expect that in any debate about religion with believers someone will eventually ask the question, "Without religion, what's to stop people from raping/robbing/murdering each other?". My first thought is usually, "Well, it's good to know that the only thing stopping you from doing those things is the fear of divine punishment." With this question in mind, I decided to look up the per capita rape and murder rates by country, as well as rates of "irreligion" in those same countries. Here's what I found:

Countries that are less religious:
Sweden
Rate of irrelegion: 88%
Murder (per 100,000): 0.7
Rape (per 100,000): 63.5

Denmark
Rate of irrelegion: 83%
Murder (per 100,000): 0.8
Rape (per 100,000): 6.4

United Kingdom
Rate of irrelegion: 76%
Murder (per 100,000): 1.0
Rape (per 100,000): ??

Japan
Rate of irrelegion: 71%
Murder (per 100,000): 0.3
Rape (per 100,000): 1.0


Countries that are more religious:
Afghanistan
Rate of irrelegion: 3%
Murder (per 100,000): 6.5
Rape (per 100,000): ??

Rwanda
Rate of irrelegion: 5%
Murder (per 100,000): 23.1
Rape (per 100,000): ??

South Africa
Rate of irrelegion: 20%
Murder (per 100,000): 31.0
Rape (per 100,000): 132.4

Mexico
Rate of irrelegion: 44%
Murder (per 100,000): 21.5
Rape (per 100,000): 13.2


United States
Rate of irrelegion: 36%
Murder (per 100,000): 4.7
Rape (per 100,000): 27.3

There is a pattern among this sample. The less religious countries have far fewer murders and, with the exception of Sweden, fewer rapes as well ( though I couldn't find rape stats for all of the countries). Of course, I'm sure you could find another set of countries that would yield the opposite results, with the less religious countries having higher rates of violent crime, but I used this set of nations to prove a point. If more religion equals more morality, how does one explain these statistics?

Sources:
http://en.wikipedia.org/wiki/Irreligion_by_country
https://en.wikipedia.org/wiki/List_of_countries_by_intentional_homicide_rate
http://www.nationmaster.com/country-info/stats/Crime/Rape-rate#country