Researching unexplained phenomena II: new evidences for anomalous experiences supported by the Multivariable Multiaxial Suggestibility Inventory-2 (MMSI-2)

Anomalous phenomena are human experiences that are characterized by challenging the foundations of current scientific ontology (i.e., psi phenomena). The problem lies in the fact that some studies have obtained significant results that support the existential validity of psi phenomena. This fact calls into question the role of psychology -and specifically that of psychological assessment- in scientifically justifying and objectively evaluating this type of behavior. This work examines the construct validity and reliability of the Multivariable Multiaxial Suggestibility Inventory-2 (MMSI-2), a psychometric test that measures both anomalous phenomena and the main psychological predictive variables that could generate them. The study included 804 participants without psychiatric history. The participants were evenly distributed into two groups: participants who believe in the existence of the paranormal and participants who are non-believers. Confirmatory factor analysis was applied, factorial invariance between both groups was examined, and Cronbach's alpha and Omega reliability coefficients were calculated. The results allowed accepting the ‘strong factorial invariance’ for the internal structure of the MMSI-2. In parallel, latent means analysis indicated that believers had higher scores than non-believers in the 4 latent variables of the test. Regression models indicated that the Clinical Personality Tendencies (CPT), Incoherent Manipulations (IMA) and Altered States of Consciousness (ASC) scales predicted 51.2% of anomalous phenomena. It is concluded that the MMSI-2, with its 174 items and 20 scales, is a valid and reliable psychometric instrument. This research is a continuation of the Escolà-Gascón (2020) report, in which the first psychometric properties of the MMSI-2 were published.