The simplest form of imitation is mere behavioral copying without realization of the benefit of the behavior. This is perhaps what guppies and octopi do, and what primates do much of the time as well. The premier copier is no doubt the chimpanzee. Juveniles in the Arnhem Zoo would amuse themselves by walking single file behind a female named Krom, which means "crooked," all with the same pathetic carriage: They also walked around supporting themselves on both wrists - instead of on their knuckles as any self- respecting knucklewalker is supposed to do - resulting in awkward locomotion similar to that of an adult male in the group whose fingers had been mangled in a fight.

Captive chimpanzees, furthermore, learn from watching people how to use tools such as hammers, screwdrivers, and brooms. That they do not always grasp the utility of the tool was noted by pioneering field-worker Robert Garner as long ago as 1896. Given a saw, his chimpanzee "applied the back of it, because the teeth were too rough, but he gave it the motion . . . He would put the back of it across a stick and saw with the energy of a man on a big salary."

It is widely assumed that primates excel at imitation - so much so that we call it aping. Usually we mean more than mere copying. Experts on primate behavior are not in agreement about the more advanced kinds of imitation, however. In its most complete form the imitator adopts the model's perspective and recognizes both the model's goal and his method of bringing this goal closer. Are monkeys or apes aware of the problems others face? Do they understand others' solutions, and can they then apply this knowledge to the same problems? Whereas there is little or no evidence that monkeys do so, some scientists believe apes to be different.

The various technologies of wild chimpanzees, such as nut-cracking with stones or termite fishing with twigs, require fine manual skills that take years to acquire (and adult chimpanzees are said to be far better at them than naive humans). Young chimpanzees seem to watch closely and learn from adults. There are even stories of mothers' correcting their offspring's mistakes, which would amount to active teaching. Unfortunately, these observations are made under uncontrolled conditions, and field-workers have a rather fragment picture of their subjects' learning histories. Experimental psychologists who have carefully tested captive chimpanzees are not convinced that such high-level processes take place. They do agree that chimpanzees pick up information from watching others (such as the location where rewards are to be obtained, and the kind of tools that produce them), and that this helps them find a solution; yet they believe that ultimately problems are solved by each individual in pendently.

The difference between chimpanzees and macaques emerging from these experiments has been corroborated by Povinelli in a telling study of role-taking. A chimpanzee was taught to select one of four handles. If she pulled the correct one, both she and a human at the other end of the apparatus would obtain food. The human but not the chimpanzee could see which handle was baited, and the human would point at this handle to assist the chimpanzee. It was a happy arrangement, and the chimpanzee soon learned to act according to the hints of her partner. After a large number of trials the roles were suddenly reversed, with the human now pulling the handles and the chimpanzee seeing the hidden food. Three of the four chimpanzees understood what was expected of them, having grasped the nature of the informant role from mere watching: they began helping their partner select the right lever. Yet when rhesus monkeys were allowed to work with human informants, none of them responded with the same sort of immediate understanding when the tables were turned: they first had to learn the new contingencies. It may be that chimpanzees can picture themselves in someone else's position and adopt this individual's role, whereas monkeys cannot.

.....Attachment, emotional identification, and innate responses, combined with potent learning abilities, provide a firm enough basis for elaborate caring behavior, which may sometimes be hard to distinguish from human expressions of sympathy. The latter differ, however, in that we recognize the other's experiences as belonging to the other, which is the only way we can feel genuine concern. A mother who shuts her eyes and grimaces when the doctor is about to stick a needle in her child's arm is anticipating the emotional disturbance of her child, hence of herself, while knowing full well that it is the child, not she, who will feel the pain. Identifying with and caring about another without losing one's own identity is the crux of human sympathy. As we have seen, this requires certain cognitive abilities, the most important one being a well-developed sense of self and the ability to assume another individual's perspective.

Two examples of simian sympathy illustrate the advantage of this ability. They describe succorant behavior of greater complexity and solicitude than found outside the human-ape branch of the primate tree.