Assessing extradyadic behavior: A review, a new measure, and two new models

An important defining characteristic of a monogamous relationship is that certain behaviors are regarded as acceptable only for the two individuals involved in the relationship. When an individual engages in such exclusive behaviors with someone outside the primary relationship without the partner’s consent, such behaviors are termed “extradyadic behaviors” (EDB). In this article, a thorough review was conducted on the measurement of EDB and the prevalence rate of EDB. It was shown that the rate of EDB varied considerably from study to study and was contingent on sample characteristics and the operational definition of EDB. Three limitations were identified in the assessment of EDB: vague terms, limited scope, and little attempt to examine the underlying structure of EDB. A new measure of EDB was developed to overcome these limitations. This new measure included a comprehensive list of clearly defined EDB, including both sexual and emotional behaviors, and both face-to-face and online EDB. Exploratory factor analyses showed that a single-factor model fit face-to-face EDB, whereas two factors were identified for online EDB: online sexual and online emotional EDB.