Over the past few decades, a decline in religious affiliation has become more pronounced in many parts of the world, particularly in the United States. One of the most significant effects of this trend is its impact on birth rates. A new analysis by Ryan Burge, a statistician and expert on religion and public life, highlights how the erosion of religious belief correlates with a decline in fertility rates. This cause-and-effect relationship has profound implications for society’s future.
Burge’s research, based on extensive data from the National Survey of Family Growth (NSFG), reveals that women who are not affiliated with any religion are significantly less likely to have children compared to their religious counterparts. For instance, among women aged 35 to 50, 53% of non-religious women have either zero or one child. In stark contrast, only 31% of Protestant women, 30% of Catholic women, and 25% of women from other religious traditions fall into this category.
The roots of this phenomenon lie in the role religion plays in shaping values related to marriage and family. As Burge points out, “Every major religious tradition has centuries of theology and instruction about the value of finding a spouse, and one common thread that runs through these traditions is the admonition to have children.” Religious beliefs often frame children as a gift and part of the natural order created by God, thereby encouraging adherents to prioritize family life.
In contrast, secular culture lacks this foundational push towards family building. With fewer religious influences, many people choose different paths, often delaying or forgoing marriage and children altogether. The data Burge analyzes shows that non-religious women are twice as likely never to have been pregnant as women from any religious tradition. This trend is more pronounced among women in their 30s and 40s, as religious affiliation has a measurable impact on fertility rates as people age.
Historically, religious communities have promoted procreation not just as a theological directive, but also as a means to sustain and grow their populations. Burge highlights how religious traditions have fostered a generational transfer of values and beliefs, which has helped maintain their cultural and social influence. However, as fewer people identify with any religious group, this generational transfer weakens, and birth rates naturally decline.
Interestingly, the impact of religious decline on fertility isn’t just a reflection of personal choice—it’s also influenced by broader sociocultural factors. Religion has long been tied to marriage rates, and people with strong religious affiliations are more likely to marry than those without. In turn, marriage is often linked to higher fertility rates. Burge’s research shows that non-religious women tend to marry later, if at all, which further decreases the likelihood of having children.
The implications of this decline are profound. As fewer people adhere to religious traditions, the cultural emphasis on family diminishes, leading to smaller families or no children at all. With lower birth rates, there are long-term societal consequences, including an aging population and potential economic challenges. Burge’s analysis suggests that this is not merely a temporary phenomenon, but part of a larger cultural shift.
Predictions about the future reinforce the importance of understanding this trend. If religious disaffiliation continues to rise, we can expect further declines in fertility rates, potentially exacerbating demographic challenges already facing many developed nations. These challenges include shrinking workforces, increased demand on social support systems, and shifts in cultural norms surrounding family life.
Burge’s work, backed by the Association of Religion Data Archives (ARDA) and supported by the Lilly Endowment, is an important contribution to understanding the complex interplay between religion and fertility. By analyzing a massive dataset and controlling for factors like education, income, race, and marital status, Burge provides compelling evidence that religious decline plays a critical role in the decline of birth rates. His findings underscore the need for continued research into how shifting cultural values impact fundamental aspects of society, such as family and reproduction.
The decline in religious belief is directly tied to a decline in birth rates. As more people move away from traditional religious frameworks that emphasize marriage and family, fewer children are being born. This shift has far-reaching consequences that will shape the future of societies around the world.
