Cognitive imitation in rhesus macaques. 
Experiments on imitation typically evaluate a student's ability to copy some feature of an expert's motor behavior.  Here, we describe a type of observational learning in which a student copies a cognitive rule rather than a specific motor action.  Two rhesus macaques were trained to respond, in a prescribed order, to different sets of photographs that were displayed on a touch-sensitive monitor.  Because the position of the photographs varied randomly from trial to trial, sequences could not be learned by motor imitation.  Both monkeys learned new sequences more rapidly after observing an expert execute those sequences than when they had to learn new sequences entirely by trial and error.