Towards a Science of Selflessness: A Scoping Review of Assessment Methods and Theoretical Perspectives

Abstract Objectives Selflessness is a multi-dimensional construct that has recently attracted growing scientific interest. However, the field remains conceptually and terminologically fragmented, and empirical assessments of selflessness are still in their early stages. This scoping review aims to systematically map the available methods developed to assess selflessness and closely related constructs, identify underlying conceptualizations, and highlight methodological gaps in the literature. Method The review was conducted in accordance with the PRISMA-ScR guidelines. Studies were eligible for inclusion if they explicitly focused on the development of assessment instruments, including self-report measures, behavioral tasks, and phenomenological interviews. Four electronic databases (Scopus, Web of Science, PubMed, and PsycINFO) were searched for articles published up to November 2024. The psychometric properties of self-report instruments were evaluated using the COSMIN guidelines. Results A total of 23 studies met the inclusion criteria. Twelve developed self-report instruments, comprising four full questionnaires, five subscales, and three pictographic scales. Additionally, three studies proposed behavioral tasks, and eight employed phenomenological interviews. The included studies reflected heterogeneous conceptual frameworks and varying methodological approaches. Conclusions The findings underscore the need for an integrated, multi-method assessment strategy that combines psychometrically sound self-report and pictographic instruments with in-depth phenomenological approaches. Developing a unified epistemological framework is also recommended to advance both research and clinical applications of selflessness. Pre-registration This review was pre-registered in the International Prospective Register of Systematic Reviews (PROSPERO). Available from https://www.crd.york.ac.uk/PROSPERO/view/CRD42023446740 .