The transition to siblinghood refers to the process wherein first-born children adjust to the arrival of a baby sibling. While welcoming a new family member is joyful, this transition can come with lower attachment security and behavioral changes. Mind-mindedness (MM), the tendency to view children as agents with independent thoughts and feelings, is important for children's socio-emotional development and secure attachment. Research has indicated that parental MM varies significantly across cultures. Therefore, in this study, we will extend current research on maternal MM, siblinghood, and focus on how maternal MM buffers the decrease in security attachment and behavioral changes during the transition into siblinghood in mainland China. 120 mother-child dyads from mainland China will be recruited, with children who are firstborns and aged under 5 and mothers in their third trimester of the second pregnancy. Mothers and children were visited twice: in the third trimester of pregnancy and 4 to 8 weeks after the sibling's birth. At each visit, mothers would be asked to finish a demographic questionnaire, Maternal Speech Sample, Children's Behavior, Firstborn-mother Attachment Security, and free play. A confirmatory factor analysis (CFA) will be used to test the validity of our measurements of attachment security. I hypothesize that the transition to siblinghood leads to negative changes in children's attachment security and behavioral adjustment, but these changes will be attenuated in the context of high maternal mind-mindedness – regression analyses will be used to examine these interaction effects.
