with the token for 'red' (a gray curved token). New symbols Premack was able to demonstrate that Sarah could understand how to decode a symbol stream after training. First, she had to learn the token name-of and then learn that some new, but real objects had the name-of fig token1 and crackerjack token2. She learned Real fig name-of fig token1 and Real crackerjack name-of crackerjack token2. She was tested with fig token1 "?" Real crackerjack which she answered correctly with fig token1 Not name-of Real crackerjack Finally, with the trainer placing a ripe fig on the table, and the tokens fig token1, crackerjack token2, give, Mary, Sarah, orange, banana, Sarah produced the new sentence Mary give fig token1 Sarah and with the trainer placing a crackerjack on the table, Sarah produced the new sentence Mary give crackerjack token2 Sarah Other concepts Sarah, Peony, and Elizabeth were able to respond to and formulate analogies and to express judgements. In these trials, problems were formulated by videotaped situations involving an actor, both friendly and unfriendly. With no training, and with observation of the laboratory only, Sarah was able to select answers requiring judgement, based on her experiences in the laboratory, such as the fact that a light cord had to be plugged in to solve some problems. Sarah was able to select proposed solutions for resolving the situations. Sarah was most accurate on judgements of sameness, less so on similarity, and least accurate on judgements of difference. Human children were then tested with the same protocols, using speech. Young children passed the tests on number, but failed on tests measuring conservation of liquid and solid. Five- to six-year-old children passed the tests on conservation of liquid and solid, suggesting a similar process for the cognition of measurement of conservation of liquid and solid, between ape and human. The conditional statement Sarah was able to parse the following sentence in a way to give her the most reward: Sarah take banana if-then Mary no give chocolate (both an apple and a banana portion are presented for Sarah to take as part of the statement) In this sentence, if Sarah were to take the apple, then Mary, the trainer, would give her the chocolate, but if Sarah were to take the banana, then Mary would not give her the chocolate. Pointing The chimpanzees do not spontaneously point outside of the psychological laboratory. The control