Empirical Study - "Elephants know when they need a helping trunk in a cooperative task"

A recent study from Frans B. M. de Waal et al. (2011) demonstrated the cognitive understanding to effectively to be aware and perform cooperative tasks in elephants. The researchers paired 12 elephants into 6 unique pairs to participate in a task that required coordinated pulling. This task was previously used to study cooperation in chimpanzees, requiring the involvement of two chimpanzees to lift a heavy weight by rope instead of only one chimpanzee. A single rope was threaded around the weight apparatus such that pulling on one end would only move the rope, not the weight, making the other end of the rope unavailable to the other partner. There were two conditions for this study: simultaneous release – where both elephants were released together from 10 meters back from the rope ends; and a delayed release – where one elephant would be released before the other, requiring a learning condition for the first elephant to wait for the second in order to perform the task correctly. This learning was taught by shaping procedures using consecutively longer intervals. All six elephants were highly successful in waiting for their partners across the 60 trials, and only increased in the longer delays after the first day, suggesting quickly learned contingency of the task regardless of the length of waiting time. The elephants inhibited their pulling response for delays up to 45 seconds, and learned that cooperation, the requirement of simultaneous pulling of the rope from both ends, was necessary to obtain the reward. These results provide ample demonstration of understanding cooperation. The researchers believe that through convergent evolutions, elephants may have reached a cooperative skill level equivalent to chimpanzees

http://0-www.pnas.org.sally.sandiego.edu/content/108/12/5116.full