A delivery device for and method of modulating a condition relating to sodal cognition and/or behaviour in a human subject using oxytocin, non-peptide agonists thereof and/or antagonists thereof, comprising: providing a nosepiece to a first nasal cavity of the subject； and providing a supply unit for administering less than 24 IU of oxytocin, non-peptide agonists thereof and/or antagonists thereof through the nosepiece to an upper region posterior of the nasal valve which is innervated by the trigeminal nerve.
