At the Anxious Bench blog, my friend and Baylor colleague Philip Jenkins suggests that American religion may finally be catching up with secular Europe, because of a key change in American families.

The United States just passed a critical statistical landmark, one that I think–I fear–has immense implications for the nation’s religious life. If I am right, and we are dealing with early days, we might seriously be looking at the opening stages of a large scale process of secularization. After being reported and speculated about for decades, that secularization might finally be happening. As I will argue, the term “secularization” over-simplifies the process, but let that stand presently.

The landmark in question concerns the fertility rate, the average number of children that a woman bears in her life. (Scholars commonly speak of the total fertility rate, TFR.) If that figure is around 2.1 children per woman, then the population will remain broadly stable, and that level is termed “replacement rate.” If the rate is much higher than that, say 5 or 6 per woman, then we will see a rapidly expanding population with many young people and young adults, with all the restlessness and turbulence that suggests. A fertility rate below 2.1 results in contracting population and an aging society. (Death rates are also significant, but less so for present purposes).

Rarely remarked even by expert observers, there is an inverse relationship between the fertility rates of a community and that society’s degree of religious fervor and commitment. High fertility societies, like most of contemporary Africa, tend to be fervent and devout. Conversely, the lower the fertility rate, and the smaller the family size, the greater the tendency to detach from organized or institutional religion. That shift from high to low commonly takes place in a short time, a generation or so. Fertility rates thus supply an effective gauge of trends towards secularization. What follows is a bare sketch, but I will deal with it in much greater detail in a book that I am currently working on–especially on issues of causation and correlation.

The classic example of demographic/religious change is modern Europe. Not coincidentally, the Europe that has become so secular since the 1960s has also, in these same years, pioneered an epochal demographic revolution of historically low fertility rates. Those rates are at their lowest in such countries as Spain and Italy, where they stand today around 1.3 or 1.4, and they have dipped well below that. Some German regions show unprecedented historic lows of 0.8. The fertility rates of nations like France and Great Britain are higher, approaching replacement, but that is because of the high fertility of recent immigrants. The rates of old-stock white populations remain universally low.

Between 1960 and 2000, much of Europe passed from a high fertility society in which religious faith and practice were both deeply ingrained to becoming deeply secularized.

Read the rest here, but from a sociological perspective, this is a fascinating and troubling development. Jenkins concedes that the big question is whether dropping fertility rates are just correlated with religious decline, or whether they somehow cause religious decline. I suspect that it is mostly a story of correlation. Why any individual or family falls away from church, or declines to get involved in church, is a highly personalized story. And Christians have to believe that the flourishing of true faith ultimately results from the movement of the Holy Spirit, who could easily cause revival in a nation of senior citizens.

Although evangelicals are not immune to these changes, most evidence would suggest that conservative Protestants (as well as Catholics and Mormons) tend to have more children than mainline Protestants and the religiously unaffiliated. This likely means that people with traditional religious views will at least continue to hold steady as a percentage of the population, even as the majority of Americans become more secular in the style of western Europeans.

Religious adherence does have a lot to do with kids. In spite of horror stories about how many youth group kids “leave the faith,” people who took a break often come back into church when they get married and start having kids. Anecdotally, I know of parents who readily admit that they only go to church for the sake of their kids. I recently had a conversation with someone who said they would not go to a certain church because of a lack of children and children’s programs. My family would certainly have to re-evaluate our involvement at our current church if we felt like their programming for teenagers was inadequate (thankfully, it is terrific).

How does all of this change when children are simply absent? Apparently much of America is getting ready to find out.

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