Relationship oxytocin therapy. Researcher Beate Ditzen at the University of Zurich, Switzerland, carrying out research on relationships. Her research has shown that the hormone oxytocin (in nasal sprays) calms couples in conflict and increases empathy and attachment. Couples that did not receive oxytocin were more stressed. Oxytocin may help promote fidelity within monogamous relationships. Photographed in 2011.