Concepts

Recent work suggests that categorical perception is not due to unique human adaptation but rather can also be found in chinchillas, macaques, and birds, suggesting that the basis for categorical perception is ‘‘a primitive vertebrate characteristic’’ (Hauser, Chomsky, and Fitch 2002: 1572), and these authors go on to observe: ‘‘Studies using classical training approaches as well as methods that tap spontaneous abilities reveal that animals acquire and use a wide range of abstract concepts, including tool, color, geometric relationships, food, and number’’ (Hauser, Chomsky, and Fitch 2002: 1575). In fact, non-human animals have been found to have a range of conceptual abilities. In their study of four wild born squirrel monkeys, Burdyn and Thomas (1984: 411) claim that these animals have ‘‘natural concepts’’ and are capable of using working memory with conceptual information, and one of their subjects was capable of remembering conceptual information for at least 16 seconds in order to make a conceptual choice. Burdyn and Thomas also draw attention to the work of Herrnstein and his associates (Herrnstein, Loveland, andCable1976) who show that pigeons in the laboratory respond reliably and discriminatively to exemplars of water (pictures of puddles, streams, lakes, etc.), trees, people, leaves, and fish even when new pictures were presented. Diana monkeys studied in the wild show referential abilities: Female Diana monkeys react with their eagle alarm call not only on eagle shrieks but also on male Diana monkeys’ eagle alarm calls (Zuberbühler, Cheney, and Seyfarth 1999: 40).

So, do non-human animals have, or are they able to acquire concepts, rather than simply perceiving associations or generalizing stimuli? Concepts have been defined in a wide range of different ways. For the purposes of the present discussion we will say that in order to understand a concept, the following abilities have to be in place:

(a) to understand that different referents are instantiations of one and the same entity;

(b) to understand that such instantiations include referents that are outside the here and now of a given situation;

(c) to use the learned entity in new contexts;

(d) to reconstruct the presence of a conceptual entity even if only parts of that entity are perceptually accessible;

(e) to produce novel instances of instances of that entity;

(f) to relate different conceptual entities to one another on the basis of size, shape, color, etc.

It would seem that these abilities can be found, in some way or other, in at least some animal species, and not just primates.

The grey parrot Alex ‘‘identified objects that differed somewhat from items used in his training; for example, although all paper initially consisted of fairly similar pieces of white, unlined index cards, he could identify pieces that varied considerably in size and shape and, without training, transferred them to items such as computer and notebook paper. Hide, wood, cork, and clothes pins (‘‘peg wood’’) were consistently identified correctly even if these items were chewed and barely resembled their original forms (Pepperberg 1999b: 45). Alex could not only respond ‘‘green’’ in the presence of a green rather than a blue object, but also knew to respond ‘‘green’’ rather than ‘‘three-corner’’ based on the type of question; ‘‘[h]e could comprehend a vocal question, extract the relevant category from the question and from an object that could be classified in multiple ways, and respond with the label for the one, correct instance of this category’’ (Pepperberg 1999b: 61).

Thus, there is evidence of the fact that animals might have a concept of an object that is not present in a given situation of interaction. A number of animals, including the grey parrot Alex ‘‘do not use symbols only for objects and actions in the here and now. They, like humans, will request an absent object, or an action not currently being performed, and accept that object or action and no other....They generally demonstrate label comprehension as well as production’’ (Pepperberg 1999b: 43). Alex consistently showed object permanence in his behavior, in that objects continued to exist when no longer in view for him, and they were unaffected by simple movement (Pepperberg 1999b: 168–85). All apes raised in human culture can refer to things not present (Miles and Harper 1994), and the gorilla Koko was able to remember events that had happened one or more days earlier and comment on them (Patterson 1978b: 197).

Extension Conceptual reasoning may also be seen in the ability of animals to ‘‘over-generalize’’, that is, to extend the use of a form–meaning pairing to referents beyond the ones canonically associated with that unit. The following are a few examples illustrating the cognitive mechanism that appears to underlie the strategy employed, which has no analog in the behavior of the human counterparts concerned:

• The orangutan Chantek used the sign LYN not only for his caregiver Lyn Miles but for all caregivers, but never for strangers, and the sign for ‘dirty’ was used more generally to refer to bad things, until he learned the sign for ‘bad’ (Miles 1990: 525–8).

• The chimpanzee Washoe used the signs she had been taught in ASL not only for specific objects or events but rather for classes of refer ents, including absent ones; for example, the sign for ‘dog’ was used to refer not only to live dogs and pictures of dogs of many breeds, sizes, and colors, but also for the sound of barking made by an unseen dog (Gardner and Gardner 1978).

• The lowland gorilla Koko extended the sign STRAW, learned initially with reference to drinking straws, to label plastic tubing, cigarettes, and a car radio antenna. She learned the sign NUT as a name for packaged nuts, but later extended it not only to roasted soybeans and sunflower seeds but also to pictures of nuts in magazines and peanut butter sandwiches. And TREE was acquired for acacia branches and celery, but was over-generalized to asparagus, green onions, and other thin objects presented vertically (Patterson 1978a: 83).

• Bottle-nosed dolphins were taught the signal HOOP in reference to a particular, large, octagonal floating plastic hoop, but they generalized immediately to hoops of different sizes, shapes, thicknesses, and colors, as well as to hoops that sink to the bottom of the tank instead of floating. The dolphin Ake was taught the sign WATER to refer to a thin stream flowing from an ordinary garden hose; when she was moved to another tank, she immediately responded to a waterfall entering the tank when WATER was used in a sentence for the first time at that new location (Herman et al. 1984; Herman 1987, 1989).

• The sign OPEN was initially used by the gorilla Koko with reference to locked doors, but was generalized to boxes, covered cans, drawers, and cupboards (Patterson 1978a: 82).

However, the possibility that these over-generalizations are due to associative rather than conceptual logic cannot be ruled out on the basis of the data that are available. That the dolphins had conceptual knowledge may be suggested by the fact that they could generalize from parts to the whole: The signal PERSON, originally taught to dolphins with reference to a particular trainer who held her arm in the water, was generalized immediately to a leg in the water, an elbow, or the whole person floating, as well as to other trainers. Note also that when one dolphin ‘‘says’’ something in reaction to a shown object, another dolphin is able to pick up another piece of the same object without knowing what the first individual saw. And these animals could also respond to an object in the absence of that object (Herman et al. 1984; Herman 1987, 1989).

That animals differ in their conceptual abilities can be seen in a com parison of the chimpanzees Sherman and Austin with the bonobo Kanzi: Whereas the former showed an ability to refer to absent objects only after specific training and no earlier than the age of 5, Kanzi was able to do so without formal training (Herman 1987: 12).

Same vs. different That there is conceptual knowledge at least in some animals is also suggested by their treatment of the comparative distinction between same and different. Squirrel monkeys (Saimiri sciureus) can associate triangularity with choosing same and heptagularity with choosing different. Burdyn and Thomas (1984) therefore conclude that for these subjects, triangularity and heptagularity were abstract symbols for same ness and difference, respectively, and the monkeys were able to represent them over intervals in which neither symbol nor referent was present. And dolphins and sea lions respond not only to novel combinations of attribute and object labels but also to novel combinations of actions and object labels (Pepperberg 1992: 301).

Pepperberg (1987a, 1992: 301, 1999b: 144) demonstrates that her trained grey parrot was able to compare objects with one another on the basis of relational concepts of ‘same’ and ‘different’, and he could discriminate between objects on the basis of color, shape, and material, for example when given the question: ‘‘What color is (item designated by shape-X and material-Y)?’’. He made these distinctions not only on known objects but also on exemplars that were novel to him. In another series of experiments, Pepperberg was able to establish that Alex distinguished fairly consistently between relative differences in the size of objects: He transposed size relationships to objects not involved in training and transferred his know ledge to items of novel colors, shapes, and sizes, and he was in a position to indicate when items did not differ in size (Pepperberg 1999b: 166–7).

One problem associated with some of the research reported above is that the animals analyzed were usually exposed to only a limited range of contexts and to tasks whose solution was predictable to some extent on the basis of the training they had received. It is unclear whether or how this affects the findings obtained.

Symbols? The term symbol is used in a wide range of works on early language as a key notion to describe or account for the specific nature of human language, but it has been defined in a number of different ways. Most of all, it has been used for:

(a) signs that, unlike indexical and iconic signs, exhibit an arbitrary relation between a meaning and a form used for its expression;

(b) objects whose reference is context-independent, including objects displaced in space and/or time (i.e. outside the here-and-now);

(c) a convention, or shared cultural understanding, whereby different symbol users interpret the symbol the same way;

(d) signs that are intentional, or at least ‘‘functionally referential’’;

(e) signs that are connected with other signs of the same kind in a network of internal relations, that is, not through relations between respective referents.

Do animals have the ability to understand and/or use entities in the sense of (a)? The answer is clearly in the affrmative:¹ Not only some great apes but also the grey parrot Alex are able to produce arbitrary form–meaning relationships (Pepperberg 1999b: 43). Savage-Rumbaugh and Lewin (1994: 160) maintain that from a very early age, the bonobo Kanzi demonstrated an understanding of a one-to-one relationship between a symbol and an object or action. Of three trained chimpanzees analyzed by Savage-Rumbaugh et al. (1980), two had acquired concepts of ‘food’ (= edibles) and ‘tool’ (= inedibles) that were functionally based, generalizable, and—as these authors argue—symbolically encoded.

Premack (1976: 165) argues that, after intensive training, the chimpanzee Sarah was able to comprehend the relationship between a ‘‘word’’ (which in his studies was a piece of plastic) and the corresponding object, for example the word for ‘apple’ and the fruit apple: ‘‘For instance, she was asked ‘Apple ? object apple’ (What is the relation between the word ‘apple’ and the object apple?); as well as the negative version of the same question, viz., ‘Apple ? object banana?’ (What is the relation between the word ‘apple’ and the object banana?).’’ The subject was able to make the correct choice between ‘‘name of’’ and ‘‘not-name of’’ at a significant rate (Premack1976: 163–4), and Premack concludes: ‘‘The fact that we could teach Sarah a property by the name of an object no less than by the actual object was, of course, highly encouraging: it was the first unqualified suggestion that the pieces of plastic had the referential function of words’’ (Premack 1971: 813).

To conclude, trained animals have the ability to acquire arbitrary mappings between signals and concepts in accordance with (a), they can learn that signs are understood as surrogates for things. And the same applies to a number of untrained animals: The calls of vervet monkeys, macaques, Diana monkeys, meerkats, prairie dogs, and chickens are suggestive of ‘‘arbitrary’’ form–meaning combinations, as Hauser, Chomsky, and Fitch suggest:

First, individuals produce acoustically distinctive calls in response to functionally important contexts, including the detection of predators and the discovery of food. Second, the acoustic morphology of the signal, although arbitrary in terms of its association with a particular context, is sufficient to enable listeners to respond appropriately without requiring any other contextual information. (Hauser, Chomsky, and Fitch 2002: 1576)

Are these calls also in accordance with (b)? Here the answer is in the negative since the calls just mentioned do not appear to be independent of the contexts in which they are used. But the situation is different in the case of trained animals if we assume that context-independence manifests itself, for example, in the fact that a signal can be used even in the absence of the object to which it refers. That Premack’s chimpanzee Sarah was able to understand the relation between a signal and an object that was not present is suggested by examples such as the following: She could select the correct color for a food item such as an apple or a banana with only the signal for that food present and the signal not being the color of the food (Premack 1976). And much the same applies to the chimpanzees Sherman and Austin, who could indicate through use of their lexigram symbols on a keyboard which one of a variety of specific foods they desired, even though no food was immediately present (Savage-Rumbaugh et al. 1980). But (b) does not only apply to primates: The grey parrot Alex was also able to produce arbitrary form–meaning relations and use them, not only for objects and actions in the here and now (Pepperberg 1999b: 43).

An interesting observation on displaced reference has been made in the case of the orangutan Chantek: He placed the object before the verb (object-GIVE) when the item referred to was present, but after the verb (GIVE-object) when the object was absent. When Chantek was eight years old, 38 percent of his signings showed displacement of reference (Miles 1990: 519, 528).

And these trained animals also comply with(c) if one assumes that they and their human caretakers are different ‘‘symbol users’’, and with (d): The findings of the researchers referred to above show clearly that there was a significant overlap in the interpretation of signals between the animals and their human counterparts, and that the signs used by trained animals are at least functionally referential, if not intentional (Hauser 1997; Johansson 2001).

But evidence that animals in captivity are able to conform to (e) is scanty. As we will see below, animals, including non-primate species such as grey parrots and bottle-nosed dolphins, are able to distinguish a range of different colors, perhaps even a term for ‘color’, but whether such terms are in fact suggestive of networks of internal relations does not become entirely clear. Perhaps the most remarkable observation that could be interpreted in favor of (e) can be seen in the taxonomic abilities exhibited by some primates, such as the ability to comprehend inclusion relations (see “Taxonomic concepts”); but one might wish to have more evidence of this sort to establish that these animals really conform to (e).

Accordingly, whether such mappings indeed qualify as ‘‘symbols’’ or words is an issue that we do not wish to decide here, considering all the discussions that have been led on this term (see especially Deacon 1997, 2003; Johansson 2001, 2002; Li and Hombert 2002; Bickerton 2003: 82–3); suffice it to cite Hurford (2003: 48), who concludes that ‘‘[a]n ape can make amental link between an abstract symbol and some object or action, but the circumstances of wild life never nurture this ability, and it remains underdeveloped.’’

There are in fact abilities that are not found in animals. Savage-Rumbaugh (1986: 13) observes that language-trained chimpanzees used pointing to request, for example, desired foods from another chimpanzee, but that there was no evidence to suggest that they comprehended the indexical or refer ring function of pointing when it was displayed to them by human experimenters. And Hauser, Chomsky, and Fitch (2002: 1576) find ‘‘that many of the elementary properties of words—including those that enter into referentiality—have only weak analogs or homologs in natural animal communication systems, with only slightly better evidence from the training studies with apes and dolphins,’’ and they conclude that additional evidence is required before the signals that have been described can be considered as precursors for, or homologs of, human words. This is largely in accordance with Pinker and Jackendoff’s (2005: 215) view according to which words are a distinctive language-specific part of human knowledge.

¹ Not everybody, however, agrees with this conclusion. Li and Hombert (2002: 177), for example, argue that non-human primate communicative signals have functions but not meanings—hence they are not symbolic. Note, however, that our concern here is not with animals in the wild but rather with the abilities shown by trained animals.

اخر الاخبار

اخبار العتبة العباسية المقدسة

العتبة العباسية المقدسة تعلن تأجيل مؤتمر معالم الحياة الطيبة عند أهل البيت (عليهم السلام) الدولي الثاني

قسم العلاقات العامة يقيم أمسية رمضانية ثقافية لطلبة الأقسام الداخلية في جامعة بابل

قسم الشؤون الفكرية ينظم ختمة قرآنية رمضانية في دولة تشاد بإفريقيا

ضمن مشروع بيوت النور.. المجمع العلمي ينظّم أمسية قرآنية رمضانية في كربلاء

المزيد

الآخبار الصحية

الماء المملح.. فائدة حقيقية أم "صيحة زائفة"؟

عادة بسيطة تدعم الصحة وتحافظ على الوزن المثالي

الغذاء النباتي يقلل مخاطر السرطان.. مع استثناء مهم

الحليب قليل أم كامل الدسم.. أيهما أفضل؟

المزيد

الآخبار التكنلوجية

أنثروبيك تتحدى البنتاغون.. وترامب يأمر بوقف التعامل معها

ميزة جديدة من "إنستغرام" لحماية المراهقين من الانتحار

الأولى من نوعها.. "تقنية مذهلة" في هاتف سامسونغ الجديد

لماذا تشعر المرأة بالألم أكثر من الرجل؟.. دراسة تجيب

المزيد

مواضيع ذات صلة

‘‘Lexicon’’

Communicative intentions

What linguistic abilities do animals have?

Some cognitive abilities of animals Introduction

Some cognitive abilities of animals

The epistemic model

Tense

Mood

The grounding predication: mood and tense

The perfect construction: [have [PERF4 [V]]]

A scenario of evolution

The final stages