Hello Master Malstrom,
What do you mean by religious? Religious can be described to many non-organized religion behaviors. Michael Crichton, author of Jurassic Park, spoke of environmentalism as religious:
The founding of the United States was a rejection of the Divine Right of Kings which is a religious belief. Europe still has royalty. They may not wield political power like they once did, but they are still there.
Since you wrote the word ‘religious’, then most Americans would say that Europe is far more religious under that general definition. However, I suspect you were referencing organized religions. There is organized religions all over the world such as South America. Why it doesn’t have as much as a presence in Europe is for you to say since I don’t know what goes on there.
The simple answer to your question is because of birth rate. Since one of the US presidential candidates is a Mormon, this is a good time to throw this in. (BTW, Clayton Christenson, who is often quoted here for his disruption literature, is a devout Mormon.) Where did the Mormons come from? They weren’t around centuries ago. They started out as a bunch of settlers that somehow got to Utah and just kept multiplying. Since the greatest transmission of values in Humanity consists through parent to child, those with the larger birth rate end up dominating.
Have you ever wondered why the Catholic Church draws the line concerning issues surrounding marriage and reproduction? You don’t see them speak out on issues of war and peace or riches and poor. Why marriage and reproduction? By keeping a multiplying flock, they not only outgrow other belief structures. They outlive nations. They’re aiming at a very long endgame.
As I understand in Europe, the population is shrinking due to low reproduction rate. Why that is, only you can say. But you asked why America is more religious than Europe. My answer is that America makes more babies. Since irreligious don’t seem to have a high birth rate (often having a negative birth rate), their populations tend to remain stagnant or drop and get outnumbered by the religious.
For evidence of what I’m saying, look at this story of why the Amish population is exploding. Centuries from now, someone might ask, “Why are there so many Amish?” and the answer will be: “Because they make babies.”