Kagan J
Arch Gen Psychiatry. 1979 Sep;36(10):1047-54. doi: 10.1001/archpsyc.1979.01780100017001.
Conceptions of psychological development devised by Western theorists have assumed connectivity of stages, stability of acquired structures, and continuity of process, and have resisted the possibility that some emerging psychological qualities might have relatively short histories. Empirical studies of the first two years of life suggest that the enhancement of retrieval memory at 8 to 10 months of age, the emergence of a linguistic set at 15 to 18 months of age, and sensitivity to standards of competence prior to the second birthday are emergent human competences that may not necessarily have a historical link to the events of early infancy. Developmental theorists should be as receptive to sequences that are relatively discontinuous as they are to those that are gradual and cumulative.
西方理论家所设计的心理发展概念假定了阶段的连贯性、习得结构的稳定性以及过程的连续性，并且排斥某些新出现的心理特质可能具有相对较短历史的可能性。对生命最初两年的实证研究表明，8至10个月大时检索记忆的增强、15至18个月大时语言集的出现以及两岁生日前对能力标准的敏感性，这些新出现的人类能力不一定与婴儿早期的事件存在历史联系。发展理论家应该像接受渐进和累积的序列一样，接受相对不连续的序列。
