The Power of an Infant\u27s Smile: Maternal Physiological Responses to Infant Emotional Expressions

Infant emotional expressions, such as distress cries, evoke maternal physiological reactions. Most of which involve accelerated sympathetic nervous activity. Comparatively little is known about effects of positive infant expressions, such as happy smiles, on maternal physiological responses. This study investigated how physiological and psychological maternal states change in response to infants\u27 emotional expressions. Thirty first-time mothers viewed films of their own 6- to 7-month-old infants\u27 affective behavior. Each observed a video of a distress cry followed by a video showing one of two expressions (randomly assigned): a happy smiling face (smile condition) or a calm neutral face (neutral condition). Both before and after the session, participants completed a self-report inventory assessing their emotional states. The results of the self-report inventory revealed no effects of exposure to the infant videos. However, the mothers in the smile condition, but not in the neutral condition, showed deceleration of skin conductance. These findings demonstrate that the mothers who observed their infants smiling showed decreased sympathetic activity. We propose that an infant\u27s positive emotional expression may affect the branch of the maternal stress-response system that modulates the homeostatic balance of the sympathetic and parasympathetic nervous systems

Adults’ Reactions to Infant Cry and Laugh: A Multilevel Study

Starting from the assumption that caregiving behaviours are regulated at different levels, the aim of the present paper was to investigate adults’ reaction to salient infant cues by means of a multilevel approach. To this aim, psychophysiological responses (Heart Rate Variability), implicit associations (SC-IAT-A), and explicit attitudes (semantic differential) toward salient infant cues were measured on a sample of 25 non-parents adults (14 females, 11 males). Moreover, the trait anxiety and the individual noise sensitivity were considered as controlling factors. Results showed that adults’ responses were moderated by the specific measure considered, and that responses at the different levels were only partially consistent. Theoretical and practical implications were discussed