The Brief Prakriti Inventory: Latent structure, reliability, and validity.

Background: Ayurveda, the traditional Indian medicine system, conceptualizes individual personality (Prakriti) through three dimensions, Vata, Pitta, and Kapha, based on physical, physiological, and psychological traits. Existing tools for Prakriti assessment often lack robust psychometric validation and accessibility. We developed and validated the Brief-Prakriti Inventory (BPI), a 21-item self-report instrument for assessing traditional Indian personality concepts. Methods: An initial 30-item pool was derived from classical Ayurvedic texts and contemporary literature, covering three domains. Following pilot testing and psychometric screening, 21 items were retained. Items used nominal response formats, each mapped to a dosha, with randomized option order via REDCap. Psychometric evaluation employed Multiple Correspondence Analysis (MCA), Latent Class Analysis (LCA), and Item Response Theory (IRT) in a community sample (N = 1857). Validity was assessed via test-retest reliability, convergent validity with traditional AYUsoft assessments, and divergent validity using Western personality traits (Mini-IPIP). Results: MCA revealed distinct dosha-aligned item clustering, particularly among participants with dominant dosha profiles ( Figure 1). LCA supported a three-class model (dominant-only: entropy R2 = 0.96) ( Figure 2, Supplementary Figure 1). IRT analyses showed strong fit (CFI = 0.967, RMSEA = 0.023) and good reliability (Vata = 0.87, Pitta = 0.75, Kapha = 0.87) ( Figure 3). Psychological items showed highest discrimination; physiological items displayed higher difficulty thresholds. Test-retest reliability was high (ICCs 0.83-0.90). BPI subscales correlated strongly with traditional assessments (r = 0.78-0.84) (Supplementary Figure 2) but minimally with Western personality traits ( Figure 4), supporting construct distinctiveness. Conclusions: The BPI is a brief, reliable, psychometrically validated self-report tool that captures latent dosha typology consistent with Ayurvedic theory. By grouping individuals into Prakriti-based clusters, the BPI will enable biological phenotyping of dosha-linked variability and support personalized, culturally contextualized interventions in integrative and mental health care.