Background: The life history of Homo sapiens is unique in having a comparatively short stage of infancy which lasts for 2–3 years. Infancy is characterized by suckling of breast milk, the development of sensorimotor cognition, the acquisition of language, mini-puberty, deciduous dentition, and almost complete skull growth. Infancy ends with the infancy-childhood growth transition (ICT) and separation from the mother. In modern-day affluent societies, breastfeeding depends on the mother’s decision and may happen at any age, and the characteristic traits of infancy have uncoupled. The data and theory for this contention are presented. Summary: The biological traits of mini-puberty and ICT characteristic of infancy occur before age 1 along with language acquisition. The cognitive (sensorimotor) component occurs by age 2, and the social component of separation from the mother by any age from 1 to 3 years. Key Messages: Human life history is based on a coherent stage of infancy which assumes coupling between the biological, cognitive, and social maturation of a baby. This is no longer the case in industrial societies and might never be so again. The upbringing of an infant needs to consider the new biology of this dissociated infancy and a new timetable of the infant’s life-history events.
Horm Res Paediatr

中文翻译：

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婴儿期生活史阶段的脱钩

背景：智人的生活史是独一无二的，其婴儿期相对较短，持续 2-3 年。婴儿期的特点是母乳的吸吮、感觉运动认知的发展、语言的获得、小青春期、乳牙和几乎完全的颅骨生长。婴儿期以婴儿期成长过渡（ICT）和与母亲的分离而结束。在现代富裕社会中，母乳喂养取决于母亲的决定，并且可能发生在任何年龄，并且婴儿期的特征已经脱钩。提出了这一论点的数据和理论。概括：小青春期的生物学特征和婴儿期的 ICT 特征随着语言习得而出现在 1 岁之前。认知（感觉运动）成分出现在 2 岁时，而与母亲分离的社会成分出现在 1 至 3 岁的任何年龄。关键信息：人类生活史基于婴儿的连贯阶段，该阶段假定婴儿的生物学、认知和社会成熟之间存在耦合。在工业社会中不再是这种情况，而且可能再也不会如此。婴儿的成长需要考虑这个分离的婴儿期的新生物学和婴儿生活史事件的新时间表。
儿科荷尔蒙