Oxytocin is a peripheral hormone and central neuromodulator that influences a number of social and affective responses relevant to social support and resilience. The Oxytocin system has been studied in numerous ways. Intranasally administered oxytocin has been found to increase optimism, trust, generosity, and empathy and to reduce anxiety (Baumgartner, Heinrichs, Vonlanthen, Fischbacker, & Fehr, 2008; Kosfeld, Heinrichs, Zak, Fischbacker, Fehr, 2005; MacDonald & MacDonald, 2010) whereas naturally occurring variation in oxytocin is associated with greater attachment and has anxiolytic effects in the context of partner support (Tops, Van Peer, Korf, Wijers, Tucker, 2007). Because only one oxytocin receptor has been identified (i.e., OXTR), the level of activity of this gene is believed to be of particular importance in regulating the activity of the oxytocin system.
