["The social milieu provides the context for the organism's survival, endurance, and adaptation. In mammals, social participation originates within the parent-infant bond and is supported by the oxytocin (OT) system, whose functioning is transmitted from parent to child through patterns of parental care. Human studies indicate that OT administration increases affiliative behavior, including trust, empathy, and social reciprocity. Here, we examine whether OT administration to parent can enhance physiological and behavioral processes that support parental social engagement but, moreover, can have parallel effects on the infant.", 'Utilizing a double-blind, placebo-controlled crossover design, 35 fathers and their 5-month-old infants were observed twice following administration of OT or placebo to father in the face-to-face still-face paradigm. Parent and infant salivary OT were assessed at multiple time points, respiratory sinus arrhythmia (RSA) was measured in the three face-to-face still-face episodes, and social behaviors of the parent and child were micro-coded for indices of social engagement.', "Oxytocin administration increased father salivary OT, RSA during free play, and key parenting behaviors that support parental-infant bonding. Parallel increases were also found in the infant's salivary OT, RSA response, and engagement behavior, including social gaze, exploration, and social reciprocity."] Does oxytocin administration to parent enhance infant physiological and behavioral readiness for social engagement?