Initial validation of the Portuguese version of the Interpersonal Behavior Questionnaire (IBQ & IBQ-Self) in the context of exercise: Measurement invariance and latent mean differences

The aim of the present research is to examine the factor structure of the Interpersonal Behavior Questionnaire (IBQ), and the Interpersonal Behavior Questionnaire Self (IBQ-Self), two scales developed for the purpose of measuring supportive and thwarting interpersonal behaviors. Structural equation modeling was used to examine the psychometric proprieties, the nomological validity with the basic needs’ satisfaction and frustration as well as the measurement invariance between gender, and differences across latent means. For the IBQ, 837 Portuguese gym members aged between 18 to 63 years old (M = 34.58; SD = 11.35) participated in this study. They had been practicing physical exercise for about 43.00 ± 37.00 months. For IBQ-Self, 612 trainers, with a professional experience that ranged from 12 to 492 months (M = 88.54; SD = 77.89), participated in this study. The analysis revealed that both scales had good fit, achieving convergent and discriminant validity. In addition, they show acceptable internal consistency and invariance between gender. Nomological validity displayed projected results, according to theoretical and empirical literature. Regarding analysis of the psychometric proprieties, IBQ and IBQ-Self can be applied to Portuguese exercisers and exercise physiologist to measure perceived behaviors from others and self-reported behaviors, respectively.