Ask The Chimps: Travel Really Does Broaden Your Mind

Chimpanzees may seem like our clownish, bumbling primate cousins, but we shouldn’t be so quick to think of ourselves as superior to them: Humans share so much DNA with chimpanzees, they are genetically more similar to us than to gorillas, their great ape cousins. Recent findings from a seven-year experiment by researchers at the University of Neuchâtel and the University of Geneva, Switzerland reveal that we may have more in common than we think. Travel, it turns out, broadens chimps’ minds, making them more innovative—and the research appears to offer key insights about human behavior and our evolutionary history.

[quote position="right" is_quote="true"]Our results show that travel fosters tool use in wild chimpanzees and it may also have been a driving force in early technological evolution by humans.[/quote]

The study, published late last month in the journal eLife, reveals that when chimps travel long distances, they are more likely to pick up the use of new tools—objects helping them acquire food or accomplish other tasks. (Common chimp tools include sticks, logs, or leaves). The longer chimps travel, research suggests, the more easily new tool use comes to them.

Previously, researchers have assumed that chimps and early humans developed new skills purely out of necessity. But primatologist Thibaud Gruber—author of the study—says it’s more nuanced than that.

“Our results show that travel fosters tool use in wild chimpanzees and it may also have been a driving force in early technological evolution by humans,” Gruber said in a statement. For seven years, he and his team studied a group of 70 pan troglodyte chimpanzees in the Budongo forest of Uganda, known for their limited tool use behavior because they have relatively easy access to their primary food source, fruit.

Gruber tested the chimpanzees using a “honey trap experiment,” in which a hole was drilled into a log and partially filled with fresh, delicious honey that could only be accessed by using a tool of some kind, as a chimpanzee’s fingers would not be long enough to reach the majority of the honey. What Gruber found was that when experimenters controlled only for necessity—i.e., the chimps were hungry—it wasn’t enough to encourage tool use.

“[A chimp] could find [a nice object] in front of him and develop tool use, but it doesn’t happen,” Gruber says. “The reason is, you’re not really motivated to engage with this problem because you know you have a nice fruit waiting for you just a minute ahead of walking.”

But chimps that had roamed were in need of high-energy food. So rather than taking the expected approach (i.e., eating literal low-hanging fruit), the challenge presented by an inaccessible treat was seen as an opportunity to innovate. Rather than ignore sticks or leaves placed nearby, the travelers saw potential in them—so much so that even after controlling for seven other factors of influence, there was a 15 to 20 percent increase in the likelihood that a chimp on a journey would use a tool.

Each panel shows the relationship between ripe fruit feeding, travel time and engagement, respectively use of tools, for time periods of 1, 7 and 13 weeks. Figure courtesy eLife.

Traveling chimps expend more energy, so perhaps they were simply more motivated to seek food on the way to their next destination. Still, says Gruber, it’s striking that the combination of necessity and opportunity made chimps so much more likely to give a new tool a try.

Jess Hartel, sanctuary director for Project Chimps in Georgia and director of conservation for the Kibale Chimpanzee Project, says the findings are all the more remarkable because, despite the reputation that chimpanzees have for being “master imitators,” those who used tools were not necessarily those who’d seen other chimps do so. Instead, they came up with their tool-based solutions entirely on their own.

[quote position="left" is_quote="true"]Chimps are really similar to us in this respect and can teach us a lot.[/quote]

Gruber sees parallels between traveling chimpanzees’ innovation process and human evolution. “Chimps are really similar to us in this respect and can teach us a lot,” he says. Gruber, who also studies how “chimps and humans represent their cultures,” suggests that human evolution may owe its advances to a similar process of traveling away from known locations in search of new food sources. Tool use and bipedalism (or walking on two feet) developed at around the same time, according to the study:

“Tool use is connected to energy gain in a changing environment and that using tools is a response to increased costs of travel and lower quality of available food. In parallel, the adoption of bipedalism, which is less energetically costly than the quadrupedal and bipedal locomotion of chimpanzees, also allowed minimizing energy expenditure. Whether their development to unrivalled levels is what led to the dispersal of early humans throughout Africa and the advent of complex technology around 3.0 million years ago remains to be investigated.”

Gruber says that in the face of climate change’s extreme effects on human environments, he expects that in the not-so-distant future, humans will evolve new adaptive techniques and skills for survival. He adds that all his research is based on data taken from “forests which are basically under threat” and where “primates are dying and communities are disappearing.” In other words, these chimps weren’t exactly traveling for leisure.

To that end, Gruber stresses the importance of conservation. “If this forest disappears, a whole culture disappears.” He may be talking about Ugandan chimps, but it’s a comment that humans would be wise to keep in mind.