During the randomization clinic visit, subjects who screen into the study will be randomly assigned (like the flip of a coin) to receive either oxytocin or placebo intranasal spray. Members of the researcher staff will instruct subjects in how to self-administer intranasal spray doses from a spray bottle. Subjects will then take their first intranasal test dose during a clinic visit scheduled shortly after this screening visit. Subjects will take an intranasal spray bottle home with them after this visit and continue to self-administer intranasal test doses three time each day (at approximately breakfast, lunch and dinner time) for two days and thereafter will take intranasal test doses twice each day (at approximately breakfast and dinner time). Each dose will be 10 sprays into their nose (5 per nostril alternating between nostrils).