V ASOPRESSIN O XYTOCIN AND “P AIR B ONDING ” The early phase of love represents an extreme neurobiological state somewhat contradictory in a physiologic sense from subsequent phases and states. Stress appears to be the trigger for a quest for pleasure, proximity, and closeness. As a norm, moderate stress encourages social interaction. Within a homeostatic range, stress-related physiologic processes including the hormones of the hypothalamo-pituitary adrenal axis can help develop and promote social bonding. Indeed, some of the signs commonly associated with love-anxiety palpitations increased peristalsis are manifestations of the stress response (albeit in a pleasurable way). Indeed, subjects in love show higher levels of cortisol when compared to controls. Irrespective, this stress response appears to be important in the formation of social contact and attachment. This “love induced hypercortisolemia” may represent a nonspecific stress response to change that characterizes early phases of relationships or a physiologic state of alertness that may help overcome neophobia Central norepinephrine may also be involved.