Forms of spirituality and their associations with conspiratorial thinking in Polish young adults

Background: Conspiracy beliefs are increasingly recognized as relevant to mental health, treatment adherence, and health-related behaviors, particularly among young adults. At the same time, patterns of spirituality in this group are shifting from institutional religiosity toward more individualized forms of spiritual practice. While spirituality is often considered a protective resource, less is known about how different forms of spirituality - religious, non-religious, and syncretic - are associated with conspiratorial thinking in young adults living in rapidly changing sociocultural contexts. Methods: We conducted a cross-sectional study among 1,100 young adults (aged 18-25 years) in Poland who were not undergoing psychiatric or psychological treatment. Based on self-declared worldview and engagement in Nonreligious Forms of Spiritual Practice (NFSP)-defined as spiritual practices pursued outside institutional religion-participants were classified into four groups: Catholics, Catholics engaging in NFSP (syncretic spirituality - Catholics Plus), atheists, and atheists engaging in NFSP - Atheists Plus. Spirituality was assessed using the Interfaith Spirituality Scale (ISS), and conspiratorial thinking with the Generic Conspiracist Beliefs Scale (GCBS). Group differences and within-group correlations between ISS domains and GCBS scores were analyzed using nonparametric methods. Results: Participants engaging in NFSP-both religious and non-religious-displayed higher levels of conspiratorial thinking than their counterparts who did not engage in such practices. The highest GCBS scores were observed in the syncretic group (Catholics engaging in NFSP), followed by atheists engaging in NFSP, Catholics, and atheists. Among Catholics, higher spirituality-particularly in the domain of asceticism and moral self-regulation-was negatively associated with conspiratorial thinking. Among atheists, ascetic spirituality also showed a protective association, whereas domains reflecting intuitive or transcendent connection were positively related to selected conspiracy belief dimensions. In both NFSP groups, higher spirituality-especially in meditation- and experience-oriented domains-was consistently associated with stronger conspiratorial beliefs. Conclusions: The findings suggest that spirituality is not a homogeneous construct in relation to conspiratorial thinking. Institutionally embedded, norm-regulated spirituality may be associated with lower endorsement of conspiracy beliefs, whereas individualized, non-religious forms of spiritual practice appear to co-occur with higher susceptibility to conspiratorial narratives among Polish young adults. These relationships should be interpreted as associational rather than causal and highlight the importance of considering the form and epistemic orientation of spirituality in research on conspiracy beliefs.