美国哈佛大学Rebecca Saxe研究组提出亲密关系的早期概念：幼儿使用唾液共享来推断亲密关系。相关论文于2022年1月21日发表在《科学》杂志上。

他们发现，儿童、蹒跚学步的幼儿和婴儿通过共享唾液（与其他积极的社会互动相反）来推断二人具有独特的关系。孩子们希望在核心家庭中共享唾液。蹒跚学步的幼儿和婴儿期望共享唾液的人会在压力中相互回应。父母证实，唾液分享是孩子社交环境中关系深厚的有效线索。因此，使用独特的互动来推断关系类别的能力在生命的早期就出现了，没有明确的教导。 这使幼儿能够迅速确定家庭内外的亲密关系。

研究人员表示，在整个人类社会中，人们形成了以强烈的依恋、义务和相互反应为特征的“深厚”关系。亲密关系中的人会分享餐具、亲吻或参与其他涉及分享唾液的独特互动。

附：英文原文

Title: Early concepts of intimacy: Young humans use saliva sharing to infer close relationships

Author: Ashley J. Thomas, Brandon Woo, Daniel Nettle, Elizabeth Spelke, Rebecca Saxe

Issue&Volume: 2022-01-21

Abstract: Across human societies, people form “thick” relationships characterized by strong attachments, obligations, and mutual responsiveness. People in thick relationships share food utensils, kiss, or engage in other distinctive interactions that involve sharing saliva. We found that children, toddlers, and infants infer that dyads who share saliva (as opposed to other positive social interactions) have a distinct relationship. Children expect saliva sharing to happen in nuclear families. Toddlers and infants expect that people who share saliva will respond to one another in distress. Parents confirm that saliva sharing is a valid cue of relationship thickness in their children’s social environments. The ability to use distinctive interactions to infer categories of relationships thus emerges early in life, without explicit teaching; this enables young humans to rapidly identify close relationships, both within and beyond families.

DOI: abh1054

Source: https://www.science.org/doi/10.1126/science.abh1054