Lawrence Josephs, Ph.D. is a professor of psychology at the Derner School of Psychology of Adelphi University and has a psychotherapy practice in New York City. His research centers on the psychology of adult romantic relationships. Josephs has been especially interested in the psychology of infidelity and the role of authenticity in successful intimate relationships. The American Psychological Association published his book The Dynamics of Infidelity: Applying Relationship Science to Psychotherapy Practice and a training video, "Restoring Trust After Infidelity.” He has also published an op-ed in the New York Times ("When the Best Sex is Extra-Marital”). Josephs regularly publishes in journals such as the Archives of Sexual Behavior, Journal of Sex and Marital Therapy, Psychoanalytic Psychology, and International Journal of Psychoanalysis on topics related to intimate relationships.
Securely attached adults seem to be good at relationships, they're more monogamous. They are more reflective, they have better communication skills, they have happier sex lives. So secure attachment seems good for sexual exclusivity.