Seyfarth Robert M, Cheney Dorothy L
Departments of Psychology and Biology, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA.
Ann N Y Acad Sci. 2003 Dec;1000:32-55. doi: 10.1196/annals.1280.004.
Historically, a dichotomy has been drawn between the semantic communication of human language and the apparently emotional calls of animals. Current research paints a more complicated picture. Just as scientists have identified elements of human speech that reflect a speaker's emotions, field experiments have shown that the calls of many animals provide listeners with information about objects and events in the environment. Like human speech, therefore, animal vocalizations simultaneously provide others with information that is both semantic and emotional. In support of this conclusion, we review the results of field experiments on the natural vocalizations of African vervet monkeys, diana monkeys, baboons, and suricates (a South African mongoose). Vervet and diana monkeys give acoustically distinct alarm calls in response to the presence of leopards, eagles, and snakes. Each alarm call type elicits a different, adaptive response from others nearby. Field experiments demonstrate that listeners compare these vocalizations not just according to their acoustic properties but also according to the information they convey. Like monkeys, suricates give acoustically distinct alarm calls in response to different predators. Within each predator class, the calls also differ acoustically according to the signaler's perception of urgency. Like speech, therefore, suricate alarm calls convey both semantic and emotional information. The vocalizations of baboons, like those of many birds and mammals, are individually distinctive. As a result, when one baboon hears a sequence of calls exchanged between two or more individuals, the listener acquires information about social events in its group. Baboons, moreover, are skilled "eavesdroppers:" their response to different call sequences provides evidence of the sophisticated information they acquire from other individuals' vocalizations. Baboon males give loud "wahoo" calls during competitive displays. Like other vocalizations, these highly emotional calls provide listeners with information about the caller's dominance rank, age, and competitive ability. Although animal vocalizations, like human speech, simultaneously encode both semantic and emotional information, they differ from language in at least one fundamental respect. Although listeners acquire rich information from a caller's vocalization, callers do not, in the human sense, intend to provide it. Listeners acquire information as an inadvertent consequence of signaler behavior.
从历史上看，人类语言的语义交流与动物明显的情感叫声之间存在着一种二分法。当前的研究描绘了一幅更为复杂的图景。正如科学家们已经识别出人类言语中反映说话者情感的元素一样，野外实验表明，许多动物的叫声为听众提供了有关环境中物体和事件的信息。因此，与人类言语一样，动物的发声同时为其他动物提供了语义和情感方面的信息。为支持这一结论，我们回顾了关于非洲绿猴、戴安娜猴、狒狒和沼狸（一种南非獴）自然发声的野外实验结果。绿猴和戴安娜猴在察觉到豹、鹰和蛇的存在时会发出声学上不同的警报叫声。每种警报叫声类型都会引发附近其他动物不同的适应性反应。野外实验表明，听众不仅根据这些发声的声学特性进行比较，还根据它们所传达的信息进行比较。与猴子一样，沼狸在面对不同捕食者时会发出声学上不同的警报叫声。在每个捕食者类别中，叫声在声学上也会根据信号发出者对紧迫性的感知而有所不同。因此，与言语一样，沼狸的警报叫声传达了语义和情感信息。狒狒的发声，与许多鸟类和哺乳动物的发声一样，具有个体独特性。因此，当一只狒狒听到两个或更多个体之间交换的一系列叫声时，听众就能获取有关其群体中社会事件的信息。此外，狒狒是熟练的“偷听者”：它们对不同叫声序列的反应证明了它们从其他个体发声中获取的复杂信息。雄性狒狒在竞争性展示中会发出响亮的“哇哦”叫声。与其他发声一样，这些高度情绪化的叫声为听众提供了有关叫声发出者的优势等级、年龄和竞争能力的信息。虽然动物的发声与人类言语一样，同时编码语义和情感信息，但它们在至少一个基本方面与语言不同。尽管听众从叫声发出者那里获取了丰富的信息，但从人类的意义上讲，叫声发出者并非有意提供这些信息。听众获取信息是信号发出者行为的无意结果。
