Institute of Child Development, University of Minnesota, Twin Cities 55455, USA.
Psychol Sci. 2012 Sep 1;23(9):1016-23. doi: 10.1177/0956797612438265. Epub 2012 Jul 24.
In the longitudinal study reported here, we examined genetic and caregiving-based contributions to individual differences in infant attachment classifications. For 154 mother-infant pairs, we rated mothers' responsiveness to their 6-month-old infants during naturalistic interactions and classified infants' attachment organization at 12 and 18 months using the Strange Situation procedure. These infants were later genotyped with respect to the serotonin-transporter-linked polymorphic region (5-HTTLPR). Maternal responsiveness uniquely predicted infants' attachment security. Infants' 5-HTTLPR variation uniquely predicted their subtype of attachment security at 12 months and their subtype of attachment insecurity at 12 and 18 months. The short allele for 5-HTTLPR was associated with attachment classifications characterized by higher emotional distress. These findings suggest that 5-HTTLPR variation contributes to infants' emotional reactivity and that the degree to which caregivers are responsive influences how effectively infants use their caregivers for emotion regulation. Theoretical implications for the study of genetic and caregiving influences are discussed.
在本研究报告的纵向研究中，我们研究了遗传和养育因素对婴儿依恋分类个体差异的贡献。对于 154 对母婴，我们在自然互动中评估了母亲对 6 个月大婴儿的反应能力，并使用陌生情境程序在 12 个月和 18 个月时对婴儿的依恋组织进行分类。这些婴儿后来根据 5-羟色胺转运体相关多态性区域（5-HTTLPR）进行了基因分型。母亲的反应能力是婴儿依恋安全性的唯一预测因素。婴儿的 5-HTTLPR 变异是 12 个月时依恋安全性亚型和 12 个月及 18 个月时依恋不安全性亚型的唯一预测因素。5-HTTLPR 的短等位基因与情绪困扰程度较高的依恋分类有关。这些发现表明，5-HTTLPR 变异影响婴儿的情绪反应，而照顾者的反应程度会影响婴儿利用照顾者进行情绪调节的效果。本文讨论了研究遗传和养育影响的理论意义。
