Apes Think More Like Humans, Study Finds

Mark Shiffer

New research suggests that apes can guess what others are thinking, a trait that has long been thought to only occur in human beings. In other words, apes have the ability to put themselves in another primate's mindset, and this can lead to empathy and more complex thinking. They can see the world from another's point of view, even if they know it's completely false.

The experiment confirmed what behavior scientists call the theory of mind. The eye movements of three apes were recorded while they watched a video of a human searching for a hidden object that had been moved without the human allegedly knowing. The apes kept looking at where the man in the video was expecting the object to be. The test results suggest the apes were able to understand what the human actor was thinking, reports Scientific American.

The video also featured a man dressed in a gorilla costume and depicted some conflict between a human and the costumed gorilla. As social animals, apes are interested in interaction and conflict between individuals. That helped to keep their attention on the video, as cameras recorded where their eyes were focused. Studying the eye movements of the apes gave scientists an idea of what the apes were thinking as they watched the action unfold.

All three species of apes successfully passed the experiment. This is significant as previous research had suggested that apes were not capable of comprehending beliefs that are untrue. Instead, apes seem to share this trait with humans, at least on a basic level, the test suggests. This could reveal that apes understand each other more than previously thought.

The findings have wider evolutionary implications as well. If modern apes have the same ability as modern humans to understand what others are thinking, that evolutionary trait can likely be traced back at least to the last common ancestor that linked humans and apes. That could mean a time from 13 to 18 million years before our own species of homo sapiens arrived, according to Quartz.

Possessing theory of mind traits gives apes and humans an advantage for survival and reproductive success. If you are able to try to predict another's behavior, you can better plan your own reactive behavior and achieve a more favorable personal outcome.

There are some practical implications from the latest research too. Further studies can look at how individual apes differ in their theory of mind skills, and a possible relation to differences in ape brain structure and genes.

The results may help with better understanding of various human disorders. In particular, there may be clues to complex neurological disorders such as autism. Some people on the autism spectrum lack the ability to infer other people's thoughts and feelings.

Apes could potentially benefit as well. Many were rescued and grew up in captivity and would not survive in the wild on their own. A better understanding of ape thought processes could help make their lives more comfortable.

The cognitive development of understanding someone else's thinking usually develops in human children at an early age. The test results on the three apes were similar to cognitive ability found in humans under the age of 2.

[Featured Image by Themba Hadebe/AP Images]