Measuring the tendency to help: Psychometric evidences of the prosocialness scale in the Brazilian context

The present research aimed to present psychometric evidence of reliability and validity for the Prosocialness Scale in the Brazilian context, both for use with adults and adolescents. As an alternative, a brief version of the measure was proposed. Through six studies, we obtained evidence of a single-factor structure, with appropriate model-fit indices, and internal consistency ranging between ω = 0.87–0.95. The short version, consisting of five items, also proved to be adequate in measuring the construct. Furthermore, item discrimination and difficulty indices were also investigated, based on the Graduated Response Model, as well as measurement invariance. Finally, the relationship between the Prosocialness Scale and Aggression was investigated, and a negative correlation with physical aggression was observed. In summary, the results indicate that the instrument is suitable for use in the Brazilian context. The scale can be applied both in the research context and in professional practice, for example, evaluating interventions on the topic.