Wisely, in our view, the only evidence for spontaneous teaching that Kline accepts is from professional records of field observations. Christophe Boesch, for example, is a veteran primatologist who has been publishing reports of wild chimpanzee behavior in respected scientific journals for more than 40 years. Boesch is best known for discovering that wild chimpanzees in Ta'i National Park, Ivory Coast, crack nuts by striking them with stones and branches that the chimpanzees specially select for use as hammers, and carefully place the nuts on rocks specially selected for use as anvils. In the course of intensive studies, he discovered that mothers of dependent infants engage in behavior much like teaching:
After successfully opening a nut, Sartre replaced it haphazardly on the anvil in order to attempt access to the second kernel. But before he pounded it, (his mother, Salome) took it in her hand, cleaned the anvil, and replaced the piece carefully in the correct position. Then, with Salome observing him, Sartre successfully opened it and ate the second kernel. Here, the mother demonstrated the correct positioning of the nut. (Boesch Reference Boesch1991, p. 531)
In a second example:
Ricci's daughter, 5-year-old Nina, tried to open nuts with the only available hammer, which was of an irregular shape. As she struggled unsuccessfully with this tool, alternately changing her posture, hammer grip, and the position of the nut, Ricci was resting. Eventually, after 8 min of this struggle, Ricci joined her and Nina immediately gave her the hammer. Then, with Nina sitting in front of her, Ricci, in a very deliberate manner, slowly rotated the hammer into the best position with which to pound the nut effectively. As if to emphasize the meaning of this movement, it took her a full minute to perform this simple rotation. With Nina watching her, she then proceeded to use the hammer to crack 10 nuts (of which Nina received six entire kernels and a portion of the other four). Then Ricci left and Nina resumed cracking. Now, by adopting the same hammer grip as her mother, she succeeded in opening four nuts in 15 min. Although she still had difficulties and regularly changed her posture (18 times), she always maintained the hammer in the same position as did her mother. She whimpered whenever encountering difficulties, to attract her mother, but Ricci did not return to her even when she threw a temper-tantrum after unsuccessfully attempting to open a fifth nut for 3 min. (Boesch Reference Boesch1991, p. 532)
We are curious to see how Kline, or others, might apply her framework to the wild chimpanzees at Gombe featured in this Animal Planet video (available at: http://www.animalplanet.com/tv-shows/jane-goodall/videos/almost-human-chimps-human-tools.htm); or to Fouts et al.'s (Reference Fouts, Hirsch, Fouts, Fitzgerald, Mullins and Gage1982) report of active teaching by the captive chimpanzee, Washoe. Washoe had begun to appropriately use signs of American Sign Language as an infant of about 10 or 11 months (Gardner & Gardner Reference Gardner and Gardner1969). When Washoe was approximately 14 years old, Roger Fouts introduced Washoe to a 10-month-old infant chimpanzee, Loulis. During the first few days after Loulis arrived, Washoe often turned toward him signing COME, approaching him, and finally grasping his arm and drawing him close. During the next five days she signed COME and only approached without touching him. After about a week, Washoe only signed COME as she turned towards Loulis, and faced him until he came to her. Washoe also molded Loulis' hands to form signs. In one observation, as a human friend was bringing candy, Washoe repeated the FOOD sign, jiggling about and grunting with excitement. Loulis was watching her. Abruptly, Washoe stopped signing, molded Loulis' hand into a FOOD sign, and moved his molded hand to his lips. Washoe formed the GUM sign with her hands, but placed it on Loulis' cheek. She also formed DRINK with her own hand and brought it to Loulis' lips, and formed HAT with her own hands and brought it to Loulis' head. In still another observation, Washoe placed a small chair in front of Loulis and repeated the CHAIR sign while watching him intently.
Other examples of direct active teaching among nonhuman animals may be relatively rare because, as Kline points out, “there are simply more studies of human teaching – and a lower bar for ‘establishing’ teaching in humans – than for any other species” (sect. 7, para. 2). The framework in the target article promises to set common standards across cultures and species, thereby permitting comparative studies that might establish functional relationships between learning problems and teaching types. We wholeheartedly agree with this approach. If teaching is a product of biology, then it is a function of variables – a highly complex function, yes; many variables, doubtless; but a function of variables, nevertheless. Logical divisions between human and nonhuman and between teaching and nonteaching seem plausible only because divisions of this kind agree with Aristotle's law of the excluded middle.
Historically, philosophers claimed that humans were unique because only humans used tools, or later, because only humans made tools (e.g., Edman Reference Edman1920, p. 15; Grzimek Reference Grzimek1977, p. 357). Each claim was eventually discredited by observations. Perhaps, Kline's framework will stimulate more reports of direct active teaching by other animals. In the meantime, we are cautious about accepting still another claim for discontinuity between humans and other animals.
Wisely, in our view, the only evidence for spontaneous teaching that Kline accepts is from professional records of field observations. Christophe Boesch, for example, is a veteran primatologist who has been publishing reports of wild chimpanzee behavior in respected scientific journals for more than 40 years. Boesch is best known for discovering that wild chimpanzees in Ta'i National Park, Ivory Coast, crack nuts by striking them with stones and branches that the chimpanzees specially select for use as hammers, and carefully place the nuts on rocks specially selected for use as anvils. In the course of intensive studies, he discovered that mothers of dependent infants engage in behavior much like teaching:
After successfully opening a nut, Sartre replaced it haphazardly on the anvil in order to attempt access to the second kernel. But before he pounded it, (his mother, Salome) took it in her hand, cleaned the anvil, and replaced the piece carefully in the correct position. Then, with Salome observing him, Sartre successfully opened it and ate the second kernel. Here, the mother demonstrated the correct positioning of the nut. (Boesch Reference Boesch1991, p. 531)
In a second example:
Ricci's daughter, 5-year-old Nina, tried to open nuts with the only available hammer, which was of an irregular shape. As she struggled unsuccessfully with this tool, alternately changing her posture, hammer grip, and the position of the nut, Ricci was resting. Eventually, after 8 min of this struggle, Ricci joined her and Nina immediately gave her the hammer. Then, with Nina sitting in front of her, Ricci, in a very deliberate manner, slowly rotated the hammer into the best position with which to pound the nut effectively. As if to emphasize the meaning of this movement, it took her a full minute to perform this simple rotation. With Nina watching her, she then proceeded to use the hammer to crack 10 nuts (of which Nina received six entire kernels and a portion of the other four). Then Ricci left and Nina resumed cracking. Now, by adopting the same hammer grip as her mother, she succeeded in opening four nuts in 15 min. Although she still had difficulties and regularly changed her posture (18 times), she always maintained the hammer in the same position as did her mother. She whimpered whenever encountering difficulties, to attract her mother, but Ricci did not return to her even when she threw a temper-tantrum after unsuccessfully attempting to open a fifth nut for 3 min. (Boesch Reference Boesch1991, p. 532)
We are curious to see how Kline, or others, might apply her framework to the wild chimpanzees at Gombe featured in this Animal Planet video (available at: http://www.animalplanet.com/tv-shows/jane-goodall/videos/almost-human-chimps-human-tools.htm); or to Fouts et al.'s (Reference Fouts, Hirsch, Fouts, Fitzgerald, Mullins and Gage1982) report of active teaching by the captive chimpanzee, Washoe. Washoe had begun to appropriately use signs of American Sign Language as an infant of about 10 or 11 months (Gardner & Gardner Reference Gardner and Gardner1969). When Washoe was approximately 14 years old, Roger Fouts introduced Washoe to a 10-month-old infant chimpanzee, Loulis. During the first few days after Loulis arrived, Washoe often turned toward him signing COME, approaching him, and finally grasping his arm and drawing him close. During the next five days she signed COME and only approached without touching him. After about a week, Washoe only signed COME as she turned towards Loulis, and faced him until he came to her. Washoe also molded Loulis' hands to form signs. In one observation, as a human friend was bringing candy, Washoe repeated the FOOD sign, jiggling about and grunting with excitement. Loulis was watching her. Abruptly, Washoe stopped signing, molded Loulis' hand into a FOOD sign, and moved his molded hand to his lips. Washoe formed the GUM sign with her hands, but placed it on Loulis' cheek. She also formed DRINK with her own hand and brought it to Loulis' lips, and formed HAT with her own hands and brought it to Loulis' head. In still another observation, Washoe placed a small chair in front of Loulis and repeated the CHAIR sign while watching him intently.
Other examples of direct active teaching among nonhuman animals may be relatively rare because, as Kline points out, “there are simply more studies of human teaching – and a lower bar for ‘establishing’ teaching in humans – than for any other species” (sect. 7, para. 2). The framework in the target article promises to set common standards across cultures and species, thereby permitting comparative studies that might establish functional relationships between learning problems and teaching types. We wholeheartedly agree with this approach. If teaching is a product of biology, then it is a function of variables – a highly complex function, yes; many variables, doubtless; but a function of variables, nevertheless. Logical divisions between human and nonhuman and between teaching and nonteaching seem plausible only because divisions of this kind agree with Aristotle's law of the excluded middle.
Historically, philosophers claimed that humans were unique because only humans used tools, or later, because only humans made tools (e.g., Edman Reference Edman1920, p. 15; Grzimek Reference Grzimek1977, p. 357). Each claim was eventually discredited by observations. Perhaps, Kline's framework will stimulate more reports of direct active teaching by other animals. In the meantime, we are cautious about accepting still another claim for discontinuity between humans and other animals.