A plethora of data supports links between parenting behaviors and child anxiety, but few studies have examined factors that can contribute to variability in these relations. Adopting a biological sensitivity to context framework, this study explored the role of children's physiological stress reactivity in the links between emotion-parenting and child anxiety symptoms in a group of Chinese families. Sixty-one parent-child dyads (child M-age = 8.21 years, SD = 1.40, range = 6-12 years) participated in an acute stress protocol, from which children's physiological (cortisol and respiratory sinus arrhythmia) responses to a social speech task were recorded. Participants then completed questionnaires assessing parents' emotion-parenting behaviors and children's anxiety symptoms. Results showed that the relation between supportive emotion-parenting and child anxiety was stronger in the context of greater child RSA suppression to acute stress, such that children higher in RSA suppression exhibited lower anxiety symptoms when supportive emotion-parenting was higher than when it was lower. Thus, these findings supported the biological sensitivity to context model. No significant moderation effect was detected for cortisol reactivity or recovery. Instead, exploratory mediation analyses showed that supportive emotion-parenting was negatively related to child anxiety via greater cortisol recovery. There was also a significant indirect path where unsupportive emotion-parenting was related to blunted cortisol recovery, which in turn was associated with higher child anxiety. The results highlight the importance of coaching parents to respond in supportive ways to children's emotional expressions, particularly in the context of greater child reactivity, to help buffer against childhood anxiety symptoms.
