New Study Reveals Great Apes' Playful Teasing - Do They Possess Humor?

February 13, 2024

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by the Max Planck Society

Babies as young as eight months old exhibit playful teasing behaviors with others. As this kind of tease play doesn't require language, analogous forms might be found in non-human animals.

Playful teasing now has been documented in four species of great apes by a team of cognitive biologists and primatologists from UCLA (USA), the Max Planck Institute of Animal Behavior (Germany), Indiana University (USA), and UCSD (USA).

Ape teasing, similar to humans' joking behavior, consists of surprise and playful elements while being provocative and persistent. Such behaviors being found in all four great ape species suggest the antecedents for humor could have emerged in human evolution at least 13 million years ago.

Teasing shares a lot of similarities with joking and can be seen as an intellectual forerunner to it. Joking is imperative to human communication as it involves social intelligence, anticipation of others' future actions, and recognizing and enjoying the breach of anticipations.

Humans exhibit forms of playful teasing as early as eight months old, before they even utter their first words. They often repeat provocations that surprise the recipient. For instance, to tease their parents, infants playfully present and withdraw objects, break minor social rules (provocative non-compliance), and disturb others' activities.

An article in the Proceedings of the Royal Society B presents a study done by researchers from UCLA, the Max Planck Institute of Animal Behavior, Indiana University, and UCSD. They showcase instances of playful teasing in orangutans, chimpanzees, bonobos, and gorillas.

Post-doctoral researcher Isabelle Laumer (UCLA/MPI-AB) first authored the study and explained that the great apes make excellent subjects for teasing research. Their close relation to humans, sophisticated understanding of expectations from others, and their expressive laughter and engaging social play make them so.

The team scrutinized spontaneous social interactions, including mild harassment, provocation, or playful incidents. The considerations included observing actions, movements, facial expressions of the one teasing, and how the receiver responded.

Observations confirmed that all four great ape species engaged in provocative behavior intentionally. Additionally, numerous characteristics of play accompanied these teasing interactions. Researchers were able to distinguish 18 unique teasing behaviors that appeared to provoke a response or focus the target's attention.

Evidence showed that orangutans, chimpanzees, bonobos, and gorillas frequently used techniques like swinging or waving an object in their target's line of sight, or hitting or poking them. Further, intrusive actions like pulling hair or halting their movements were also common.

Senior author of the study, Erica Cartmill, a professor at UCLA and IU, noted that playful teasing differs from playing. She explained that teasing tends to be one-sided and usually originates from the teaser, with little reciprocation from the target. She also observed a marked absence of play signals like the primate 'playface' and 'hold' gestures.

Similar to human children, playful teasing in apes involves a provocateur, response waiting, repetition, and elements of surprise. Encouragingly, this kind of teasing mostly occurs when apes are relaxed, striking a similarity with human behavior.

The study indicates that the field primatologist Jane Goodall and others had documented comparable behaviors in chimpanzees years ago. However, this new study is the first to systematically investigate playful teasing.

'From an evolutionary perspective, the presence of playful teasing in all four great apes and its similarities to playful teasing and joking in human infants suggests that playful teasing and its cognitive prerequisites may have been present in our last common ancestor, at least 13 million years ago,' explains Laumer.

'We hope that our study will inspire other researchers to study playful teasing in more species in order to better understand the evolution of this multi-faceted behavior. We also hope that this study raises awareness of the similarities we share with our closest relatives and the importance of protecting these endangered animals.'

Journal information: Proceedings of the Royal Society B

Provided by Max Planck Society