1) young children tend to imitate both the necessary as well as the unnecessary actions when shown how to get at a reward, whereas wild chimpanzees only imitate the necessary actions.
2) both 14-month old human infants as well as enculturated, human raised-chimpanzees tend to ‘imitate rationally.’ That is, they tend to be able to differentiate whether an agent chose a specific way of performing an action intentionally, or whether the agent was forced to performing the action in this specific manner by some constraint.
Range F, Viranyi Z, & Huber L (2007). Selective imitation in domestic dogs. Current biology : CB, 17 (10), 868-72 PMID: 17462893