The hormone oxytocin, which is released in social bonding and touch, functions like a dimmer switch, influenced by the situation, according to researchers. A study of 42 women found oxytocin levels were higher when their partners stroked their arms first, then fell, only to increase again when a stranger did the same thing. When the stranger touched their arms first, there was no change in oxytocin levels. The research has implications for administering synthetic oxytocin, such as in nasal sprays, to treat mood-affecting conditions.