Individual-level changes in religious/spiritual beliefs and behaviours over three decades in the parental generation of the ALSPAC cohort, UK

Longitudinal data on religious/spiritual beliefs and behaviours (RSBB) are essential for understanding both how religion shapes our lives and the factors determining religiosity. Despite this importance, there are few longitudinal studies with detailed and repeated RSBB data. Using data spanning nearly 30 years from the parental generation of the Avon Longitudinal Study of Parents and Children (ALSPAC) based in the Southwest of England, we describe individual-level changes in various aspects of self-reported RSBB (religious belief, affiliation, and attendance, among others) measured on four occasions (pregnancy, plus 5, 9 and 28 years post-partum; approx. 3,600 mothers and 1,200 partners have data at all four time-points). Although RSBBs were generally consistent over time, a shift towards non-religiosity was observed; exceptions included Roman Catholic affiliation, which was remarkably stable over three decades, and religious attendance, which increased from pregnancy to 5 years, before declining at 28 years. Most changes in RSBB were minor, e.g., between ‘yes’ and ‘not sure’ regarding religious belief, rather than between ‘yes’ and ‘no’. We also provide a simple illustrative example of how these longitudinal data can be analysed. In addition to describing these longitudinal patterns, this paper will help inform future research using ALSPAC’s longitudinal RSBB data.