“I may have seen a horsefly, yea I’ve seen a dragonfly, but I ain’t never seen an elephant fly.”-from Disney’s “Dumbo” (my favorite movie at age 1).
But have you seen an elephant cooperate? Cooperation is problematic for biologists. While Darwin readily acknowledged that cooperation was prevalent in many species (e.g. honeybees), yet he could not invoke the same selective pressures that shaped most selfish behaviors in explaining cooperative ones. It was not until the latter part of the past century with the work of biologists such as Hamilton, Trivers, and Wilson did the scientific community begin to understand the causal principles of cooperative acts. Hamilton provided biologists with the mathematics to understand inclusive fitness, and by extension how cooperative behaviors might be selected for over time. While cooperation does not require vast cognitive capabilities, coordinating/collaborating during problem solving tasks is a bit more demanding. Coordination requires some understanding of the mental state of others as well as their intentions. A recent paper published by Plotnik and colleagues (2012) in PNAS suggests that elephants have developed coordinated problem solving skills similar to chimpanzees.
In this paper, the researchers presented a pair of captive Asian elephants (Elephas maximus) with a cooperative problem solving task originally used in primate research (Melis et al. 2006). Each elephant in the pair would be given opposite ends of a rope. If both elephants pulled the rope at the same time, then both elephants would get a food reward by moving a sliding table towards their enclosure. The rope-table apparatus is constructed in such a way that if only one elephant pulls his/her end then the table does not move and neither elephant gets any food. In other words, the elephant pair is presented with a dilemma. Pulling the rope gets you food, but only if you work together. Here is a lovely sketch of the test from the paper.
To determine if the elephants actually learn that coordination results in maximum benefit (getting the food), the researchers exposed elephants to three test conditions. In the first condition, both elephants would be released simultaneously to see if they would pull the rope to get the reward. This condition is not very informative, since the elephants might both simply be acting with the rule, “Pull the rope, get the food, don’t worry about what your neighbor is doing.” The true scientific test is in the second two tests: (1) “delayed release” and (2) “no-rope control” (Plotnik et al. 2012). In the “delayed release” condition, the first elephant was forced to wait until its partner was released so they could jointly pull the rope to get the food. If the first elephant pulled the rope without his/her partner, then they failed to coordinate their behavior. In the “no-rope control” both elephants were released at the same time, however only one partner had access to the rope. In this condition, the task was impossible to solve. Instead researchers were interested in whether or not the elephant with the rope would inhibit their behavior given the situation of their rope-less partner. Not suprisingly, the elephants waited for their partners up to 45 seconds in the “delayed release” condition and did not pull the rope at all (almost) in the “no rope” control. These results suggest that elephants have at least some understanding of “partner oriented, deliberate cooperation” on the level with chimpanzees and humans (Plotnik et al. 2012)
Now I’ve seen just about everything.
This papers is also currently Open Access through PNAS. Follow the link HERE.
Plotnik, J., Lair, R., Suphachoksahakun, W., & de Waal, F. (2011). From the Cover: Elephants know when they need a helping trunk in a cooperative task Proceedings of the National Academy of Sciences, 108 (12), 5116-5121 DOI: 10.1073/pnas.1101765108
Melis AP, Hare B, & Tomasello M (2006). Chimpanzees recruit the best collaborators. Science (New York, N.Y.), 311 (5765), 1297-300 PMID: 16513985
