Investigating the causal effects of religiosity on childbearing among U.S. adolescents using a three-wave longitudinal design

While rich on correlational findings, the existing literature contains limited evidence for a causal effect of religiosity on fertility. We examined the causal effects of religiosity on fertility using longitudinal data from the National Study of Youth and Religion. Specifically, we tested the effects of religious change between 2003 and 2005 on subsequent reproductive behavior until 2013 among 3,365 young Americans. Controlling for baseline covariates and baseline attendance in 2003, attending church weekly and more often in 2005 was associated with higher fertility in 2013. Further analyses suggested that the positive effect of religious attendance on fertility is present among men but not among women. Similarly, we found that considering faith very or extremely important was associated with higher fertility among men but not among women. Overall, the observed effects were weak and on the edge of statistical significance. We discuss the implications of our findings for theorizing about the function of religions in human societies.