The Study of Orangutans Sheds Light On How Human Curiosity May Have Evolved

 

Great apes are curious in captivity, but cautious around unfamiliar objects in the wild, according to new research.

 

The study was published in the journal Scientific Reports, and the researchers claim it is the first to measure orangutans' responses to novelty in the wild. It follows the behavior of human-acquired orangutans in a Sumatra reserve.

 

Great apes in captivity usually spend a long time exploring new objects. However, researchers had little idea how that curiosity would play out in the wild.

Previously, scientists planted novel items throughout the forest at Suaq Balimbing, a protected biodiversity area in Sumatra where conservation biologists monitor orangutans. However, in previous experiments, the apes were so wary of the new items that the experiments failed.

 

Recently, biologists devised a more enticing method of pique the orangutans' interest by planting a piece of tree trunk filled with local forest honey on trees near the orangutans. The scientists then observed the apes as they encountered the familiar but intriguingly novel object over the course of 170 trials.

The biologists discovered that the orangutans' ways of expressing their curiosity differed depending on their age. Immature orangutans looked at the object "significantly longer" than other apes, for an average of 233 seconds, compared to 103 seconds for mothers and 34 seconds for sexually mature males. Immature orangutans were also faster to approach the object and displayed agitation while doing so.

 

The apes rarely touched the branch, instead using a tool like a stick. In areas where food was plentiful, they were also less likely to approach the honey-stuffed branch.

However, their curiosity appeared to be influenced by social connections: when an orangutan was accompanied by another ape, it was more likely to approach and touch the object.

 

According to a press release, the findings shed light on how human curiosity may have evolved.

 

"We often think of learning and innovation as solo acts, but this might not have been the case in our early history," said Caroline Schuppli, director of the Suaq Balimbing orangutan research project and the study's first author. "If novelty was the spark, then our social lives might have provided the accelerant."