CATEGORIZATION IN MONKEYS AND CHIMPANZEES - IELTS Reading Answers & Explanations

You should spend about 20 minutes on Questions 14-26, which are based on Reading Passage 2 on the following pages.

CATEGORIZATION IN MONKEYS AND CHIMPANZEES

A Humans have a natural propensity to detect relations of similarity and difference among objects and events of the physical world and to build categories that embody these relations. We exhibit such ability in everyday life: to identify new objects, to acquire information from the environment, to solve problems, to effectively communicate with other individuals. Categorization is, in essence, one of the most basic ways to organize our knowledge adequately.

B To treat discriminably different environmental stimuli as similar and to recognize a group of things as members of the same class is a capacity displayed to some extent by all animals. All species, in fact, must be able to make same/different distinctions in order to recognize predators, edible foods, nests, conspecifics and so on. Non-human primates not only distinguish predators and non-predators, but actually identify the predators more specifically. As for some of the social behaviours that non-human primates display in both free-ranging and captive settings, these animals can form abstract categories of their social world. For example, monkeys classify social bonds according to abstract concepts such as kinship or friendship.

C As it is shown above, primate species possess complex cognitive abilities that enable them to make abstract judgments when interacting with their environment. Nevertheless, these cognitive skills animals use to detect identity relations between artificial stimuli may be limited. Identity relations in monkeys are confined to physical resemblance among individual stimuli; great apes, on the other hand, are capable of both concrete and abstract relations.

D Many studies clearly demonstrate that there are important differences in the degree to which monkeys and apes process same/different relations. Monkeys have a limited capacity for the abstract representation of identity relations between objects. Although these animals can be taught to match a small set of stimuli on the basis of physical likeness, the generalization of the matching concept from learning situations to totally new classes of stimuli is not very strong. Monkeys' ability to extrapolate an identity rule is limited to values that lie on dimensions similar to those of training. Classificatory behaviour of monkeys seems more likely to be mediated by stimulus-specific associations than to be based on conceptual mechanisms. Further evidence for such cognitive constraints comes from data on object sorting behaviour. Composing objects into single sets characterizes monkeys' spontaneous constructive interactions with objects throughout their development. Consequently, their classificatory behaviour does not progress beyond first-order classifying. More significantly monkeys do not develop elementary second order classifying, that is, the capacity for coordinating class relations simultaneously. This failure implies severe limitations in the way monkeys conceptually structure objects with which they interact and has serious implications as regards the development of representational skills.

E A different picture emerges when we consider the behavioural patterns non-human primates display in free-ranging settings. Descriptions of competitive and cooperative interactions with conspecifics, as well as other aspects of their social behaviour, often suggest that monkeys are capable of classifying social stimuli into abstract categories. It thus seems that monkeys display a capacity for abstract representation when interacting with their social environment, a capacity not observed when they are dealing with physical stimuli. But can they really handle abstract concepts such as kinship or friendship similar to the way humans do? It is conceivable that monkeys' social knowledge is based on relatively simple associative learning rather than represent the result of more complex cognitive process. Knowledge of other animals' social relationships may be obtained principally by observing and memorizing all the specific interactions among members of one's own social group. A monkey can learn to associate some individuals with others on the basis of specific behavioural patterns that these animals display with a high frequency and adjusts its own behaviour accordingly.

F Chimpanzees, by contrast, behave quite differently. When tested on relatively similar tasks requiring comprehension of an identity rule, they display complex cognitive capacities never observed in monkeys. Chimpanzees not only can detect similarities and differences between individual objects at a more abstract level than monkeys, but they can also perceive same/different relations between pairs of objects from a very early age and do so without any specific training. This perception of abstract relationships is reminiscent of findings obtained in studies with human infants. For example, when preference for novelty procedures is employed, 7-month-old infants were found to be sensitive to identity/different relationship instantiated between pairs of stimuli. It thus seems that cognitive competence underlying perceptual categorizing in infant chimpanzees is similar to that found in human infants.

G In apparent contrast with monkeys, moreover, chimpanzees make use of abstract judgments in their constructive interactions with objects: without training or rewards they spontaneously partition the sets they receive into classes coordinating relationships simultaneously.

H The simultaneous construction and coordination of two class-consistent spatial groupings is an index of more advanced cognitive organization. It is considered symptomatic of an advance in logical reasoning indicating the simultaneous consideration of the part to the whole. In humans this capacity progresses from constructing one class at a time, comparing individual objects in terms of their similarities and differences, to constructing classes of classes simultaneously coordinating such comparisons. This behavioural shift marks the transition from prerepresentational to representational cognition.

I It seems that a similar development marks the ontogeny of manipulatory classification of chimpanzees. Like children, these apes show a developmental trend from first-order to second-order classifying, that is, a trend from object-based similarity to relational similarity.

J Nevertheless, although humans and chimpanzees seem to share the basic components of logical cognition, at least in the realm of categorization, the two species vary markedly in the staging of development of classificatory behaviour. The onset age for second-order classifying is the 2^nd year in human infants; the onset age is the 5^th year in chimpanzees. It thus seems that chimpanzees' development is much slower than children's, which perhaps indicates that a limit is being approached.