Department of Ethology, Eötvös University, Jávorka S. u. 14., H-213, Göd, Hungary.
Anim Cogn. 1998 Oct;1(2):113-21. doi: 10.1007/s100710050016. Epub 2014 Jan 5.
Since the observations of O. Pfungst the use of human-provided cues by animals has been well-known in the behavioural sciences ("Clever Hans effect"). It has recently been shown that rhesus monkeys (Macaca mulatta) are unable to use the direction of gazing by the experimenter as a cue for finding food, although after some training they learned to respond to pointing by hand. Direction of gaze is used by chimpanzees, however. Dogs (Canis familiaris) are believed to be sensitive to human gestural communication but their ability has never been formally tested. In three experiments we examined whether dogs can respond to cues given by humans. We found that dogs are able to utilize pointing, bowing, nodding, head-turning and glancing gestures of humans as cues for finding hidden food. Dogs were also able to generalize from one person (owner) to another familiar person (experimenter) in using the same gestures as cues. Baseline trials were run to test the possibility that odour cues alone could be responsible for the dogs' performance. During training individual performance showed limited variability, probably because some dogs already "knew" some of the cues from their earlier experiences with humans. We suggest that the phenomenon of dogs responding to cues given by humans is better analysed as a case of interspecific communication than in terms of discrimination learning.
自奥弗·普丰斯特（O. Pfungst）的观察以来，动物利用人类提供的线索在行为科学中已广为人知（“聪明汉斯效应”）。最近的研究表明，猕猴（Macaca mulatta）无法将实验者的注视方向用作寻找食物的线索，尽管经过一些训练后，它们学会了对手势的反应。但是，黑猩猩会利用注视方向。狗（Canis familiaris）被认为对人类的手势交流很敏感，但它们的这种能力从未经过正式测试。在三个实验中，我们检验了狗是否能够对人类提供的线索做出反应。我们发现，狗能够利用人类的指点、鞠躬、点头、转头和扫视手势作为寻找隐藏食物的线索。狗还能够从一个人（主人）推广到另一个熟悉的人（实验者），使用相同的手势作为线索。我们进行了基线测试，以测试仅气味线索是否可以解释狗的表现。在训练过程中，个体表现的可变性有限，这可能是因为有些狗已经从与人类的早期经验中“知道”了一些线索。我们认为，狗对人类提供的线索做出反应的现象最好通过种间交流来分析，而不是通过辨别学习来分析。
