["Journal for the Scientific Study of Religion, Volume 60, Issue 3, Page 516-539, September 2021. ", "\nAbstract\nEvidence is widespread of declining religiosity measures in many countries, including some outside of Europe. Is this a transition toward secularity among general populations, or instead a change in the nature of individual spiritualities? This question is addressed by this study with International Social Survey Programme data spanning 27 years (1991–2018) and 46 nations. Many measures of religiosity and belief are found to be declining in most countries, supporting secular transition theory. Identifying as spiritual but not religious remains a minority phenomenon in areas with low levels of religiosity, but an important phenomenon nonetheless that has seen some growth. We argue here that there is a way forward in these data to understand secular transition and individual spiritualization theories as complementary, not conflicting.\n"]