A growing body of demographic research finds a clear association between declining religiosity in the United States and the nation’s falling birth rate, adding a cultural dimension to well-known economic explanations for fewer children. Recent reporting and data syntheses – notably a long-form piece in Newsweek summarizing experts’ views, a detailed demographic analysis posted by the Institute for Family Studies, and new estimates from the Pew Research Center’s 2023–24 Religious Landscape Study – show that Americans who are more religious tend to have larger families, while the religiously unaffiliated have had markedly fewer children in recent decades. At the same time, the number of people who identify as nonreligious has grown, meaning the fertility gap by religion now helps explain a meaningful share of the overall decline in U.S. births. These trends matter to Thailand because Thai fertility has fallen even more rapidly, and understanding cultural as well as economic drivers can help shape policies to stabilise family formation and cushion the social effects of population ageing. See the Pew report here, the Institute for Family Studies analysis here, and the CDC’s 2023 birth data here.
Demographers and social scientists point to three linked developments that explain the U.S. pattern. First, religiosity remains correlated with higher completed fertility: the new Pew Religious Landscape Study finds that among adults aged 40–59, Christians report an average “completed fertility” of about 2.2 children, while religiously unaffiliated adults report about 1.8 children on average (Pew RLS executive summary). Second, the share of Americans who are religiously unaffiliated has grown steadily for decades (Pew reports about 29% unaffiliated in its 2023–24 RLS), and younger cohorts are much less religious than older ones; when a growing share of the population holds lower-fertility values, overall birth rates fall even if the fertility of religious subgroups remains stable (Pew RLS executive summary). Third, the fertility gap itself has widened over time: survey-based estimates that track births and religious attendance show weekly religious attenders having fertility at or near replacement levels historically, while the nonreligious have fertility at very low levels (Institute for Family Studies overview and historical NSFG-based estimates; see IFS analysis and related research using National Survey of Family Growth data).
The timing of these findings matters because U.S. births reached near-historic lows in the early 2020s. The U.S. National Center for Health Statistics reports about 3.6 million births in 2023, a decline from previous years and a general fertility rate down to roughly 54.5 births per 1,000 women ages 15–44 in 2023 (CDC rapid-release and PubMed summary; see also CDC data brief here). Analysts link a patchwork of causes to that decline — cost of living and housing, delayed marriage, changing gender roles, and the pandemic shock — but the new line of work on religion highlights an additional social and cultural force reshaping fertility over the long term.
What the data show, in concrete terms, is striking. Using the National Survey of Family Growth and more recent surveys, researchers estimate that women who attend religious services weekly have had roughly double the number of children compared with women who say they never attend, and that nonreligious women’s fertility has plunged in the last decade to levels comparable with the lowest-fertility East Asian societies. The Institute for Family Studies’ synthesis concludes that “virtually 100% of the decline in fertility in the United States from 2012 to 2019 can be explained” by growing irreligion and falling fertility among the nonreligious, combined with conversions out of religion that change the composition of the reproductive-age population (IFS blog). The same analysis calculates that, because many religious traditions in the U.S. also lose people through conversion, religious communities would need average fertility of around 2.44 children per woman to maintain size across generations; most do not meet that threshold, suggesting institutional decline over time absent immigration (IFS blog).
Researchers offer several mechanisms to explain why religiosity and higher fertility travel together. Religious practice is associated with earlier and higher rates of marriage, stronger pronatalist norms (explicit teachings or cultural expectations favoring larger families), community structures that support child-rearing (congregational networks, religious schools, mutual aid), and a value framework that places greater emphasis on family continuity. The Pew Religious Landscape Study collects direct evidence of religious child-rearing practices: among parents who are highly religious, a large majority pray or read scripture with their children and prefer religious education or private/religious schooling at much higher rates than parents who identify as nonreligious (Pew RLS parent activity findings). Those practices both reflect and reinforce family-centered lifestyles that are correlated with higher fertility.
At the same time, experts caution that religiosity is only a piece of a larger puzzle. Economic insecurity, the cost of housing and childcare, women’s improved educational and labour-market opportunities, delayed marriage, and changing gender norms are major independent drivers of low fertility. An American Economic Association review described the post‑recession decline in US births as a complex puzzle shaped by the economy, demographics and social change, not by any single cause (AEA Journal of Economic Perspectives review). The Congressional Budget Office’s long-term projections also show fertility continuing at low levels for decades under a variety of economic scenarios, underscoring the structural challenges of reversing national birth declines solely through cultural shifts (CBO demographic outlook).
Experts quoted in recent coverage frame the relationship between religion and fertility as both a demographic fact and a policy challenge. The Institute for Family Studies’ analysis bluntly notes that even if religious groups retain higher fertility, conversion and secularisation trends mean that those groups alone cannot offset national declines unless fertility rises substantially or immigration patterns change (IFS blog author commentary). Pew researchers similarly highlight the demographic consequences of a less religious young cohort: younger Americans are far less likely to be religious than older cohorts, and the “stickiness” of a religious upbringing has weakened, meaning fewer young people who were raised religious stay that way into adulthood; these shifts have long-term implications for both religiosity and the social behaviours associated with it, including fertility (Pew RLS executive summary).
How does this U.S.-based research matter for Thailand? Thailand’s demographic slide is steep and already advanced: United Nations and World Bank numbers show Thailand’s total fertility rate (TFR) has fallen well below replacement for years, with recent World Bank and national estimates placing the TFR near or below about 1.2–1.3 births per woman in the early 2020s (World Bank World Development Indicators and national statistics; see World Bank data portal for fertility here; FRED series summarised here). Thai authorities reported fewer than half a million births in 2022 — the lowest annual total in decades — prompting public discussion and policy responses (VOA Thai reporting on Thailand’s low births). In short, Thailand is even further along the low‑fertility trajectory than the U.S., so lessons about cultural determinants of fertility are directly relevant.
Thailand differs from the U.S. in important cultural ways. The majority of Thais identify as Buddhist, and Buddhist temples historically serve as social and intergenerational anchors in communities — hosting rites of passage, childcare support from extended family networks, and moral frameworks around family life. Yet Thailand also has seen rapid urbanisation, rising educational attainment (especially among women), smaller household living arrangements, and changing aspirations among young people — all of which push down fertility. There is also evidence that younger Thais are less likely to participate in traditional temple life in the same way older generations did, paralleling the U.S. picture in which younger cohorts are less religious than their elders in practical terms, even when cultural affiliation remains high. For readers interested in the Thai data, see the World Bank fertility time series (World Bank TFR for Thailand) and reporting on Thailand’s 2022 births decline (VOA).
The policy takeaway is twofold. First, cultural institutions — whether churches in the United States or temples and community organisations in Thailand — can matter for family formation because they provide social norms, networks and practical support that make childbearing and child-rearing more feasible and socially desirable. Policymakers who want to influence fertility outcomes should therefore consider how to mobilise and partner with community groups while preserving secular, rights‑based governance. Second, cultural levers alone are unlikely to reverse low birth rates without complementary economic and social policies. International evidence and domestic experience show that affordable, high‑quality childcare, more generous parental leave, flexible work arrangements, housing support for families, and financial incentives that reduce the marginal cost of an extra child are the more direct levers governments can use; multiple studies and policy reviews emphasise these points (see OECD and country-level policy literature; for U.S. context, see the CBO outlook here and the AEA review here).
Practical steps Thai readers and policymakers could consider, based on the research and cross‑national evidence, include: strengthening publicly subsidised childcare to lower the cost of working parenthood; expanding and making more flexible parental leave policies so both parents can share caregiving without career penalties; incentivising family-friendly workplace practices, including part‑time work and remote options in urban sectors; investing in affordable housing for young families; and building local community programmes (working with temples and volunteers) that provide peer networks and practical supports for new parents. These measures should be designed to be inclusive of people of all beliefs and family forms; the aim is not to promote religion, but to replicate the social supports that religious communities often provide. Scholars who study demographic change have argued that “making parenthood more attractive” requires a combination of such economic and social interventions rather than attempting to reverse deep cultural shifts alone (IFS recommendations and analysis).
Looking ahead, several plausible scenarios emerge. If secularisation in the U.S. and other middle‑ and high‑income countries continues while economic and housing pressures remain, fertility will likely stay low and ageing will accelerate, increasing dependency ratios and straining pension and health systems. On the other hand, policies that lower the direct costs of children and improve work–family balance can mitigate the decline even without reversing secularisation. For Thailand, the window to act is narrow: its fertility is already among the lowest in Asia, and demographic inertia means that population ageing will deepen in the coming decades absent decisive policy shifts. Successful responses will be those that combine material support for families with efforts to rebuild joyous, practical community ties around child‑raising — whether through secular neighbourhood services or partnerships with temples and civil society.
For Thai readers making personal decisions about family formation, the immediate practical advice is straightforward: assess family budgets carefully; learn about available government supports for parental leave and childcare; discuss flexible working arrangements with employers; seek community networks (including temple communities and local parent groups) for informal childcare and mutual support; and, when possible, plan housing and career timing with an eye toward the real costs of raising children in your locality. For policymakers, the research suggests shifting attention from only demographic slogans to concrete policy packages that lower the financial and logistical barriers to having children, while ensuring that measures respect individual choice and social pluralism.
The emerging research linking declines in religiosity to lower fertility in the United States does not claim religiosity is the sole cause of demographic decline. But it does add an important cultural lens: as societies secularise, the social scaffolding that historically supported larger families can erode, and unless that scaffolding is replaced by inclusive public supports, birth rates are likely to remain depressed. For Thailand — where fertility is already far below replacement and where temples and extended families once supplied much of that scaffolding — the lesson is to combine community-strengthening efforts with solid, evidence-based family policies if the nation hopes to stabilise its population trajectory and sustain intergenerational support systems. For the U.S., demographers warn that relying on religion alone to restore population growth is unrealistic; demographic futures will be shaped as much by housing markets, childcare systems and labour policies as by church pews and temple courtyards.
Sources cited in this report include the Newsweek coverage summarising experts’ views (see Newsweek summary linked via MSN aggregation), the Institute for Family Studies analysis of religious‑secular fertility divergence (IFS blog), Pew Research Center’s 2023–24 Religious Landscape Study and its analysis of religion and fertility (Pew RLS summary and RLS executive summary), U.S. birth statistics and rapid‑release reports from the National Center for Health Statistics and CDC (NCHS 2023 births summary and CDC data brief db507), and Thailand fertility and birth reporting from the World Bank and VOA (World Bank TFR for Thailand; VOA Thailand births report). Additional context on economic drivers and long‑term demographic projections draws on a published review of falling U.S. birth rates in the American Economic Association’s Journal of Economic Perspectives (AEA JEP review) and the Congressional Budget Office’s demographic outlook (CBO).