Conrad Hackett, associate director for research and senior demographer, discusses why we studied the relationship between religion and happiness, health and civic engagement.
The Yazidis who have been fleeing the advance of the Sunni militant group ISIS in Iraq are a religious group of uncertain numbers and a long history of persecution.
As of 2012, at least 17 nations have police that enforce religious norms. Religion police forces are most common in the Middle East and North Africa, and are also found in the Asia-Pacific and in sub-Saharan Africa.