The goal of the present study was to identify the most important jealousy-evoking partner behaviours and to examine the extent to which these behaviours evoke jealousy. Based on the literature, a questionnaire was constructed containing 42 jealousy-evoking partner behaviours, including a partner's extra-dyadic involvement with someone else by means of modern communication devices, such as the Internet. A second study examined the extent to which undergraduates and a community sample experienced jealousy in response to these partner behaviours. Results showed that explicit unfaithful behaviours evoked most feelings of jealousy, followed by a partner's emotional or romantic involvement with someone else by means of modern communication devices. In general, older individuals responded with less jealousy in response to a partner's unfaithful and suspicious behaviours. Clinical implications are discussed. Copyright © 2009 John Wiley & Sons, Ltd. Key Practitioner Message:
A partner's involvement with someone else by means of modern communication devices may evoke strong feelings of jealousy, in particular among women.
An individual's age affects the extent to which he or she experiences jealousy in response to specific extra-dyadic partner behaviours.
In order to correctly diagnose and treat pathological jealousy, clinicians should pay attention to the extent to which partners (unintentionally) evoke and maintain feelings of jealousy.
Identifying partner behaviours that evoke most jealousy may help couples define the boundaries of their relationship.