Beginning in the 1960s the first systematic projects dedicated to testing whether great apes could acquire some aspects of human language were conducted. The ape subjects demonstrated remarkable capacities to learn and use elements of either sign language or an artificial language. The results from research across several laboratories drew a mixture of excitement and skepticism, and critiques and debates have ensued since the earliest reports were published. This continues today. Terrace (2019, Nim: A chimpanzee who learned sign language. New York, NY: Columbia University Press) repeats many of the same points made decades earlier, and has added some additional critiques. That scientists hold different perspectives on what to conclude from ape language studies is expected. However, any conclusion one draws should be based upon available evidence, which we outline in this review. We also address the critiques offered by Terrace (2019), including the stance that apes cannot understand or use words. Focusing on symbol use by chimpanzees and bonobos we describe evidence that argues for understanding of words, including capacities for declarative communication and intersubjectivity found in these apes. We conclude that the many decades of research using a variety of symbol systems challenges the absolutist position that chimpanzees and bonobos cannot learn language or understand the concept of a word.

中文翻译：

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单词很重要：对带有黑猩猩的语言项目的思考及其影响。

从1960年代开始，进行了第一个系统化项目，致力于测试大猿是否可以掌握人类语言的某些方面。猿类受试者表现出了出色的学习和使用手语或人工语言元素的能力。多个实验室的研究结果引起了人们的兴奋和怀疑，自从最早的报告发表以来，随之而来的是批评和辩论。今天继续。露台（2019，尼姆：学习手语的黑猩猩。纽约，纽约：哥伦比亚大学出版社）重复了几十年前提出的许多相同观点，并增加了一些其他批评。希望科学家对猿语言研究的结论有不同的看法。但是，任何得出的结论都应基于现有证据，我们在本次审查中对此进行了概述。我们还解决了Terrace（2019）提出的批评，包括猿类无法理解或使用单词的立场。我们以黑猩猩和bo黑猩猩的符号使用为重点，描述了为理解单词而辩护的证据，包括在这些猿类中发现的表达能力和主体间性。