stimuli is a topic that has attracted interest in recent years (e.g., Hulse, 1978). Because patterned auditory stimuli are easy to generate with currently available electronic equipment and because such stimuli are independent of reinforcement modalities, they may prove useful in the pursuit of this interesting area (see also Chapter 11, this volume, by Hulse, Cynx, & Humpal).
Although it was once thought that animals had only a limited appreciation of past events, it is now clear that many species excel in what has come to be called "episodic" memory, memory for specific past events. And it may not be outlandish to suggest that "semantic" memory might also be considerable in some species ( D'Amato, 1977). But although animals' appreciation of the past can be formidable, their contemplation of the future seems rudimentary at best. Using performance on delay of reward and delay of punishment tasks as indices, we have argued that monkeys and other animals are poorly disposed toward developing foresightful behavior, meaning by the latter the capacity to act in terms of the future rather than the present utility of objects or events ( Cox & D'Amato, 1977; D'Amato & Cox, 1976). Where an animal's relationship to its environment requires that it act in terms of the future utility of objects or events, the appropriate mechanisms apparently have been built into the organism, e.g., hoarding, deposition of fat prior to hibernation, etc. Acting in terms of the future rather than the present utility of objects or events is something that does not come easy even for humans. Such foresightful behavior seems to depend upon our ability to imagine future scenarios, and it would be interesting to see whether, for example, we could train apes to "save for a rainy day."
There is a natural, and quite understandable, tendency of investigators to stress the cognitive accomplishments of the animal subjects with which they are most intimately connected. So much so, that one must be careful that reported complex cognitive processes are not "in the eyes of the beholder." (Anthropomorphism used to be the accusation.) During our 17 years of research experience with cebus monkeys, which Premack ( 1978) has referred to as the poor man's chimpanzee, we have alternated between marvelling at their cognitive accomplishments and being plunged to the depths of despair over their inability or extraordinary reluctance to learn a variety of apparently simple tasks. Over and over again, a monkey exposed to a task somewhat different from that on which it previously exhibited expert performance would perform miserably, and only after weeks or months of intensive training would the animal acquire the new task, Even when the transitions from one task to another were aided by shaping techniques, this problem often occurred. Thus, in addition to the apparent cognitive limitations mentioned above, it must be added that cebus monkeys (andother monkeys as well are not spontaneously flexible creatures. It is true that they can be taught flexibility by means of a learning-set approach, but this, too, becomes rather specific to the task at hand. Related to, and 'possibly a cause of, this inflexibility is the strong