Aristotle once described elephants as "the beast which passeth all others in wit and mind," and now researchers appear to have more evidence to support that notion. Elephants seem to share with humans a hard-wired ability see a person point in a direction and turn their attention that way.
With no apparent training or preferential breeding, elephants interpret this human gesture as "look here" or "go there," something humans' closest relatives, great apes and chimps, do not do in the wild.
Such nonverbal gestures play a key role in the development of children before they learn how to speak, says Richard Byrne, a professor of psychology and neuroscience at St. Andrews University in Scotland who, along with graduate student Anna Smet, conducted the study.
No one has seen any species other than humans use this form of communication naturally, he says in an interview. For elephants, "the skill has to come from somewhere."
"We're now thinking that this must come from the natural communication system of elephants, although pointing has never been described in the wild. But they do a lot with their trunks that could, in principal, function as pointing," he says.
Humans have harnessed the power of elephants for thousands of years to do everything from hauling logs to waging war. Indeed, this remarkable history has presented a puzzle, Dr. Byrne explains: How is it that elephants can work well with people without being specifically bred for the work?
Over the years, researchers have found in elephants a high level of intelligence, strong social ties, a capacity for compassion and cooperation, and a range of other advanced mental skills, even a capacity for producing abstract art.
As with many types of dogs, an apparently innate ability to interpret human signs could have come through the elephants' long association with humans, some argue, instead of having some far deeper evolutionary origin.
To test the idea, Ms. Smet and Dr. Byrne turned to 11 elephants that ferried tourists to and from Victoria Falls, on the Zambezi River, the boundary between Zambia and Zimbabwe.
The elephants were born in the wild but rescued by Wild Horizons, a safari operator in the area, from efforts to kill off the animals to control the size of herds or from situations were an elephant wandered into a human settlement and would have been killed.
The elephants had been trained to respond to voice commands, but when not schlepping tourists, they fed in the bush and so had minimal contact with their handlers, the researchers say. Indeed, over the three months Smet spent with the elephants and their handlers, she never observed them using gestures to direct the pachyderms.
In the experiments, the elephants were presented with two buckets, one of which had been filled with food outside their view. Smet then used several types of gestures, varied her distance from the baited bucket, and even tried to use gaze alone to let the elephants know which bucket to approach.
The animals responded to the gestures at levels better than chance. The strongest response, getting to the right bucket 67.5 percent of the time, came when Smet used a fully outstretched arm and pointer finger. Two-year-old humans respond to that same gesture about 72.7 percent of the time, the researchers note.
The elephants didn't respond well to the use of gaze and head direction as a pointer.
The duo was able to rule out the elephants' sense of smell as the food detector by having Smet not point at anything. No elephant did better than random chance in finding the baited bucket.
“We always hoped that our elephants ... would be able to learn to follow human pointing," Smet said, in a prepared statement. “But what really surprised us is that they did not apparently need to learn anything. Their understanding was as good on the first trial as the last, and we could find no sign of learning over the experiment.”
The results contradict those from experiments with Asian elephants, the team acknowledges. Other researchers looking for response to gestures in Asian elephants have found none.
Part of that may stem from differences in the design of the experiments for each type of elephant, Byrne says. Or it could be that the elephants at Wild Horizons have a simpler background compared with elephants in Thailand, where gestural experiments have been conducted. The Thai elephants come out of the logging industry and where they are intensively trained to follow the foot movements of the handlers riding on them.
"Maybe they just don't bother to look at things like this anymore," Byrne says.
As to how African elephants might have developed rudimentary gestures, Byrne refers to past experiments he's conducted that test an elephant's response to bad smells or potentially alarming stimuli. The first elephant to sense danger or a foul odor would raise his or her trunk in an S shape, with the S pointing in the direction of the stimulant.
Most researchers have interpreted that as the elephant picking up the scent in what they've dubbed the "periscope sniff," Byrne says.
That may be the initial reason for hoisting a trunk, Byrne acknowledges.
"But that also shows where the elephant's attention is directed," he adds, noting that others in the herd begin to look in that direction. The trunk's shape may not mimic Smet's outstretched arm, but it serves the same purpose for the rest of the herd, he suggests.
Whatever the explanation, "Our findings suggest that elephants seem to understand us humans in a way most other animals don’t,” he says.