Parallel Life Syndrome: An Exploratory Mixed-Methods Study of Conceptual Development, Preliminary Psychometric Validation of the Parallel Life Syndrome Inventory, and Phenomenological Characterization

Abstract

Background:

Psychological concepts like dissociation, maladaptive daydreaming, or narrative identity do not well describe experiences of persistent parallel or alternating self-narratives with retained meta-awareness. We created the Parallel Life Syndrome Inventory (PLSI) as a preliminary research tool and propose Parallel Life Syndrome (PLS) as an exploratory multidimensional psycho-cognitive construct to enable systematic examination of these experiences. PLS should not be viewed as a diagnostic tool because it is currently just meant to be a hypothesis-generating construct.

Objective:

The objectives of this study were to conduct a preliminary psychometric evaluation of the recently created Parallel Life Syndrome Inventory (PLSI), develop an interdisciplinary conceptual framework for Parallel Life Syndrome through systematic synthesis of the literature, and investigate the phenomenological traits of people reporting persistent parallel self-experiences.

Methods:

Three complimentary phases of an exploratory sequential mixed-methods study were carried out. First, evidence for identity multiplicity, self-referential cognition, dissociation, and metacognitive awareness was gathered using a systematic literature review that adhered to PRISMA 2020 principles. Second, the results guided the creation of the 30-item Parallel Life Syndrome Inventory (PLSI), which was tested psychometrically in 180 adult participants who were purposefully selected. Construct validity, exploratory factor analysis, internal consistency, and sample adequacy were evaluated. Third, the participants' lived experiences were contextualized and interpreted using qualitative phenomenological case analyses.

Results:

The suggested construct has a conceptual basis thanks to the systematic review's identification of recurrent theoretical themes including identity multiplicity, self-referential processing, and metacognitive awareness. The data's eligibility for exploratory factor analysis was supported by the PLSI's outstanding preliminary internal consistency (Cronbach's α = 0.97), great sample adequacy (Kaiser-Meyer-Olkin = 0.97), and substantial Bartlett's Test of Sphericity (χ² = 3335.8, p < 0.001). While there was a slight positive correlation (r = 0.33, p < 0.001) between PLSI scores and perceived stress, there were weak correlations with established measures of dissociation, maladaptive daydreaming, anxiety, depression, and sleep quality. This suggests that the PLSI may capture experiences that are not fully captured by current instruments. Parallel self-narratives were routinely found by qualitative studies, which also retained insight, and retained meta-awareness across participants, complementing the quantitative findings.

Conclusion:

The current study offers first proof that the Parallel Life Syndrome Inventory may be used to operationalize Parallel Life Syndrome as an exploratory multidimensional psycho-cognitive entity. Together, the qualitative analysis, early psychometric results, and systematic review provide an integrated conceptual framework for further research. Crucially, the suggested neurocognitive and neurobiological mechanisms covered in this publication are speculative and were not specifically investigated in this investigation. Therefore, rather than being confirming, the results should be understood as creating hypotheses. Before considering any clinical or diagnostic use, independent psychometric validation, confirmatory factor analysis, longitudinal studies, multicentre studies, and multimodal neurobiological research are necessary.