Poking and prodding to get a reaction (behaviors common in children (and some adults)) were among the primate playful behaviors. Have you ever touched someone’s far shoulder, watched them turn the wrong way, and then done it again? Why is this funny? You might think that finding something like this funny is an innate human trait, along with the complex communication and context required to make a joke, but you’d be wrong.

New research published in the journal Proceedings of the Royal Society B, found evidence of monkey business in four great ape species (sorry), shedding light on the evolutionary origins of humor.

The findings suggest that the playful sarcasm exhibited by babies as young as eight months old may have deeper roots in our primate relatives than previously thought. Such behavior involves deliberate violation of the expectations of others; for example, repeated offering and withdrawal of objects or interfering with the activities of others deliberately and with the element of surprise.

To explore this behavior, the team observed spontaneous social interactions among orangutan, chimpanzee, bonobo and gorilla populations. They analyzed everything from the teaser’s body movements and facial expressions to how the subjects responded to the tease (taunt?) in turn.

Additionally, researchers attempted to examine the intent behind the act of teasing, whether it was aimed at a specific person, whether it continued or escalated over time, and whether the teaser expected a reaction from the person.

“Our results support the idea that teasing in great apes is a provocative, intentional, and often playful behavior,” he said. BBC Science Focus Isabelle Laumer, PhD student and lead author of the study. “It is often asymmetrical and can take different forms with varying proportions of playful and aggressive features.”

In total, researchers have identified 18 different types of regiments. This involved repeatedly shaking or shaking objects in the center of the target’s field of vision, hitting or pushing them, staring intently at the face, and pulling hair – how cute!

Unlike the games exhibited by animals in the animal kingdom, playful teasing has many unique characteristics. “In great apes, playful teasing is one-sided and largely driven by the tease,” explained Erica Cartmill, senior author of the study.

“Animals also rarely use play signals, such as the primate ‘play face’, which is similar to what we might call a smile, or ‘hold’ gestures that signal their intention to play,” he continued.

Cartmill recalled that he first saw this behavior in great apes in 2006, when he watched a baby orangutan attack its mother by constantly waving a stick in front of it. “It didn’t feel like a prank that would be the subject of a Netflix special, but it felt like a simple prank on a little kid,” she said.

Almost 20 years after this interaction, this research has revealed important information about the behavior of not only the monkeys, but also our own. “Depending on the species, great apes share 97 to 99 percent of our DNA, and we have a lot in common,” Laumer said.

“The presence of playful sarcasm in all four great apes and its similarity to playful teasing behavior in infants suggests that playful sarcasm and its cognitive prerequisites may have been present in our last common ancestor at least 13 million years ago.”

Moving forward, Laumer and his team plan to investigate whether other primate species and large-brained animals tease each other, hoping to better understand the evolution of this important (and very interesting) behavior.