Religiousness worldwide: translation of the Duke University Religion Index into 20 languages and validation across 27 nations

Abstract

Religiousness and spirituality are important in the study of psychology for several reasons: They are central to identity and values; they have been reported as being positively associated with health and well-being; and they capture (and perhaps lead to) the largest measurable psychological differences between societies. At five items, the Duke University Religion Index (DUREL) is an efficient measure, which advantageously distinguishes between religious sentiment and activity, and between formal versus private involvement. This project extends its internal validation throughout the world, with formal tests of measurement invariance in three languages in Namibia (Study 1) and in a global sample of 26 countries (Study 2). Results confirmed a two-subscale factorial structure of Religious Activity (combining organizational and non-organizational activities) and Intrinsic Religiosity in Namibia and in half of the 26-country samples. In 13 other countries, fit was best for a one-factor model. Fit was problematic where there was too little intra-national variance: in China and Japan, where religious involvement is universally low, and in Tanzania, where it is universally high. Scalar measurement invariance was found for the one-factor structure across 13 samples and for the two-factor structure across 11 samples. External validation of the scale is examined using psychological and sociodemographic variables. This validation of the DUREL supports its use across contexts, facilitating increased attention to this important aspect of both personality and culture.

The factor structure of the Duke University Religion Index: Continuing the conversation.

“…The decision to test a two-factor model—in addition to single- and three-factor models—was based on the statistical–theoretical tension already described. Several prior research teams identified a two-factor, best-fitting statistical model for their DUREL data—combining Items 1 and 2 into one factor and Items 3, 4, and 5 into a second factor (Cruz et al, 2017; Toscanelli et al, 2022). In addition, a conceptual justification may be made for a two-factor model, in that the first two items of the DUREL measure religious behaviors, while the remaining three items measure religious motivation.…”

“…A Google Scholar search revealed that the short form of the SCSRFQ has been cited 206 times, while the original DUREL article has been cited over 1,000 times. In addition, although the SCSRFQ has been translated into Spanish, Portuguese, Italian, Czech, Polish, German, Chinese, and Farsi (Plante, 2021), the DUREL has been translated into over 20 languages (Toscanelli et al, 2022). These facts highlight the importance of continuing the conversation about the psychometrics of the DUREL.…”

“…More recently, Thomas et al (2018) conducted a PCA with the DUREL in a sample of U.S. veterans, resulting in a single-factor model. Numerous studies investigating the factor structure of various translations of the DUREL concluded that the best-fitting model was unidimensional: Chinese (Chen et al, 2014), Polish (Dobrowolska et al, 2016), Turkish (Esat et al, 2021), Farsi (Hafizi et al, 2013), European Portuguese (Martins et al, 2021), Malay (Nurasikin et al, 2010); Persian (Saffari et al, 2013), college students across 11 countries (Toscanelli et al, 2022).…”

“…On the other hand, several investigations of the DUREL's factor structure have yielded a best-fitting two-factor model, including the Filipino version (Cruz et al, 2017), the Korean version (Kim et al, 2021), and two African language versions (Toscanelli et al, 2022). In these cases, DUREL Items 1 and 2 loaded on one factor (religious activity or behavior; RB), while Items 3, 4, and 5 loaded on a second factor (IRM).…”

“…Allport and Ross (1967) originally proposed the concept of IRM to be the extent to which individuals “live [their] religion”—in other words—the extent to which religion gives their lives ultimate meaning or is the most important motivating force in their lives. The DUREL has been translated into over 20 languages (Toscanelli et al, 2022), enabling it to be used worldwide in religion and spirituality research.…”