Drumm P, Gardner B T, Gardner R A
Am J Psychol. 1986 Spring;99(1):1-29.
Ten positive, five neutral, and five negative events were presented to two chimpanzees, Tatu (female, 64 months old) and Dar (male, 56 months old), who had been cross-fostered from birth by human beings. Each event was announced in American Sign Language 10 s before. The announcements and events were common items in the cross-fostering routines and were administered according to a balanced design over a period of 2 months. Vocal and signed responses to the announcements and to the events were recorded. The likelihood of either mode of response depended on affective charge, and the likelihood of vocal and signed responses was positively correlated. Signed responses were more likely than vocal responses; signed responses were more likely to be evoked by announcements than by events, whereas vocal responses were more likely to be evoked by events than by announcements. The type of vocal response depended on the affective charge and on whether the response was immediate (to the event) or anticipatory (to the announcement). Incorporation of signs and phrases from the announcements, and reiteration of signs and phrases within an utterance depended on affective charge, just as they do for human children.
向两只从小由人类交叉抚养长大的黑猩猩——塔图（雌性，64个月大）和达尔（雄性，56个月大）展示了10件积极事件、5件中性事件和5件消极事件。每件事件在10秒前用美国手语宣布。这些宣布和事件是交叉抚养日常活动中的常见项目，并按照平衡设计在2个月的时间内进行。记录了对宣布和事件的发声及手语反应。任何一种反应方式的可能性都取决于情感负荷，并且发声和手语反应的可能性呈正相关。手语反应比发声反应更有可能出现；手语反应更有可能由宣布引发而非事件，而发声反应更有可能由事件引发而非宣布。发声反应的类型取决于情感负荷以及反应是即时的（对事件）还是预期的（对宣布）。正如人类儿童一样，在话语中融入宣布中的手势和短语以及对手势和短语的重复取决于情感负荷。
