The Seven Sides of the Triangle: Development of the Multidimensional Extra-Relational Behaviors Questionnaire

Abstract

Infidelity in couple relationships is a common event, and one with potentially serious consequences for those involved. In spite of its importance, there is a scarcity of instruments for its psychological evaluation, which it would be important to compensate for. For that purpose, the Questionario Multidimensional de Comportamentos Extrarrelacionais (QMCER; Multidimensional Extra-Relational Behaviors Questionnaire) has been developed, and is composed of 6 sections. Principal components analyses (N≥156) sustain the idea that the QMCER can evaluate the occurrence of 3 types of extra-relational behaviors (sexual involvement, affective involvement and sexual desire), 7 dimensions associated with infidelity characteristics, motivations, and consequences, and 4 factors related to motivations for fidelity, which are organized in a way compatible with self-determination theory. Cronbach alpha values are generally adequate, with the exception of a few scales that need further development. Correlations among the scales and with other instruments provide good indications regarding the validity of the QMCER.