RESUMO
How mothers respond to infants' distress has implications for infants' development of self-regulation and social competence. In a sample of 35 mothers and their 4- to 8-month-old infants, we induced infant distress using an arm restraint task and compared infants' observed affect and physiological responses under two conditions, when mothers were instructed to respond with: 1) positive affect and 2) negative affect. Based on theoretical and empirical support, we empirically evaluated two opposing hypotheses. Based on the Mutual Regulation Model and work on affect matching, we predicted that when mothers respond with negative affect versus positive affect, distressed infants' duration of negative affect would be smaller, negative affect would be less intense, and respiratory sinus arrythmia (RSA) withdrawal would be lower. Based on social referencing theory and research, we expected that when mothers respond with positive affect versus negative affect, distressed infants' duration of negative affect would be smaller, negative affect would be less intense, and RSA withdrawal would be lower. We found that when mothers responded to their distressed infants with negative affect versus positive affect, infants spent significantly more time in negative affect, their intensity of expressed negative affect was greater, and their RSA withdrawal was greater, suggesting that mothers' display of mild positive affect when infants are distressed may be helpful for infants. The current findings add to accumulating evidence that mothers' positive relative to negative affective response to their infants' distress can produce observable differences in infants' duration and intensity of negative affect, as well as their physiology. Findings have the potential to inform future research that investigates how mothers can most effectively reduce their infants' distress and intervention that targets the moment-to-moment behaviors in mother-infant reciprocal interactions.