Margaret Chalmers

Are monkeys logical

THE monkeys status as a thinker has never been high; yet laboratory investigations testify, nevertheless, to the ability of many species of monkey to learn complex tasks, if not to reason. On this latter point, however, hard evidence is significantly lacking. One reason for this is that it is difficult to devise tests which are both meaningful to non-verbal subjects yet satisfy the stringent requirements of a formal reasoning test such as one adapted from Burt1 which first gives the subject the following information: “Edith is fairer than Suzanne”, “Edith is darker than Lili”, and then requires solution of the question, “which is the darkest, Edith, Suzanne or Lili?”. Bryant and Trabasso2 have devised a simplified method of giving such tests to very young children, and we have adapted this into a non-verbal one for use with monkeys.

Are Children Any More Logical Than Monkeys on the Five-Term Series Problem?.

Abstract Six-year-old children were tested on several versions of the five-term transitivity problem as used by B. O. McGonigle and M. Chalmers (1977, Nature (London) , 267 , 694–696) with squirrel monkeys as subjects. Both binary and triadic versions of the tests were administered in both verbal and nonverbal modes to help determine whether or not any major procedural differences between the monkey version and that used conventionally in research with children might account for the monkeys apparently nonlogical solution of the problem. The main result is that children showed very similar response profiles to that of monkeys in all the conditions used. In addition, “labeling”, direct seriation, and “association” post-tests suggest that nonlogical strategies can underwrite ostensibly impeccable transitive “reasoning” in child as well as monkey.

Concurrent disjoint and reciprocal classification by Cebus apella in seriation tasks: evidence for hierarchical organization

We report the results of a 4-year-long study of capuchin monkeys (Cebus apella ) on concurrent three-way classification and linear size seriation tasks using explicit ordering procedures, requiring subjects to select icons displayed on touch screens rather than manipulate and sort actual objects into groups. The results indicate that C. apella is competent to classify nine items concurrently, first into three disjoint classes where class exemplars are identical to one another, then into three reciprocal classes which share common exemplar (size) features. In the final phase we compare the relative efficiency of executive control under conditions where both hierarchical and/or linear organization can be utilized. Whilst this shows a superiority of categorical based size seriation for a nine item test set suggesting an adaptive advantage for hierarchical over linear organization, Cebus nevertheless achieved high levels of principled linear size seriation with sequence lengths not normally achieved by children below the age of six years.

The Growth of Cognitive Structure in Monkeys and Men

There is a widespread view that the sorts of animal learning mechanisms most frequently studied in the laboratory are inductively too weak and unproductive to generate the kinds of behaviours expressed in higher order forms of human cognitive and linguistic adaptation (Chomsky, 1980; Fodor & Pylyshyn, 1988; Piaget, 1971). One reason for this (Harlow, 1949) is that investigations are rarely followed through from one learning episode to another to assess the cumulative benefits (if any) as a function of the agent’s task and life history. Yet the course of human development is protracted, and even sophisticated adult subjects frequently show dramatic changes in strategy when confronted with many problems of the same type, detecting pattern and structural invariance in some (e.g., Wood, 1978), using analogies to bridge problems of a different surface structure (Gentner, 1983), and devising progressively economic, data reducing procedures to secure success with the least investment in resource (Anderson, 1990; McGonigle & Chalmers, 1996, McGonigle & Chalmers, 1998; McGonigle & Chalmers, 2001). Whilst Harlow’s pioneering work on the learning set (LS) using primates is an exception, indicating the vast potential for accelerated learning, his generative claim that the LS leaves the organism free to attack problems of a new hierarchy of difficulty has never been properly realised due to the fact that all problems in conventional LS studies are of the same (simple binary) type and level of difficulty (but see Terrace this volume).

The Selective Impact of Verbally Communicated Criteria in Orientation Judgements by Young Children

In a series of tests requiring judgements of orientation, the impact of a verbally transmitted equivalence criterion (e.g. “Pick me out the one exactly the same as this one”) was compared with one which specified the ‘identity’ of the target as a ‘standing up’ or ‘lying down’ pattern. When a subset of four-year-olds was given the latter instruction, their performance improved dramatically (although all stimuli were lying flat on a horizontal surface) but reverted to a previous (low) level when equivalence instructions were reintroduced. The results suggest that findings from equivalence tests cannot be used to make unambiguous inferences concerning the competence of young children to make identification judgements.