The Pew Research Center just released a study on
the age gap in religiosity around the world. By most measures, young adults tend to be less religious than older adults. This is true in the U.S.A. as well as in many other countries, but there is variation across countries. The full report in pdf can be found
here.
The younger are less religious in forty-one countries, including the U.S.A., Canada, Mexico, much of South America, many countries in Western Europe, Russia, and Australia. In only two countries -- Chad and Ghana -- are the older less religious. In the other countries there is no difference or no data available.
What does this mean about the future of religion around the world? The report states this:
The widespread pattern in which younger adults tend to be less religious than older adults may have multiple potential causes. Some scholars argue that people naturally become more religious as they age; to others, the age gap is a sign that parts of the world are secularizing (i.e., becoming less religious over time). (For a detailed discussion of theories about age gaps and secularization, see Chapter 1.)
But even if parts of the world are secularizing, it is not necessarily the case that the world’s population, overall, is becoming less religious. On the contrary, the most religious areas of the world are experiencing the fastest population growth because they have high fertility rates and relatively young populations.
Previously published projections show that if current trends continue, countries with high levels of religious affiliation will grow fastest. The same is true for levels of religious commitment: The fastest population growth appears to be occurring in countries where many people say religion is very important in their lives.