Apes have a sense of humor just like us

By Stephen Beech via SWNS

Apes have a sense of humor - just like humans, suggests a new study.

Researchers have found that four species of great apes - orangutans, chimpanzees, bonobos and gorillas - playfully tease each other.

The team of cognitive biologists and primatologists found that similar to joking behavior in humans, ape teasing is provocative, persistent, and includes elements of surprise and play.

Because all four great ape species used playful teasing, the research team says it is likely that the prerequisites for humor evolved in the human lineage at least 13 million years ago.

The researchers explained that joking is an important part of human interaction that draws on social intelligence, an ability to anticipate future actions, and an ability to recognize and appreciate the violation of others’ expectations.

They said teasing has much in common with joking, and playful teasing may be seen as a "cognitive precursor" to joking.

The first forms of playful teasing in humans emerge even before babies say their first words, as early as eight months of age.

Infants tease their parents by playfully offering and withdrawing objects, violating social rules - known as provocative non-compliance and disrupting others’ activities.

The new study, published in the journal Proceedings of the Royal Society B, was conducted by scientists from the University of California Los Angeles, Indiana University, the University of California San Diego and the Max Planck Institute of Animal Behaviour in Germany.

Study first author Dr. Isabelle Laumer said: “Great apes are excellent candidates for playful teasing, as they are closely related to us, engage in social play, show laughter and display relatively sophisticated understandings of others’ expectations."

The researchers analyzed spontaneous social interactions that appeared to be playful, mildly harassing, or provocative.

During the interactions, the team observed the teaser’s actions, bodily movements, facial expressions, and how the targets of the teasing responded in turn.

They also assessed the teaser’s intentionality by looking for evidence that the behavior was directed at a specific target, that it persisted or intensified, and that teasers waited for a response from the target.

The team found that orangutans, chimps, bonobos and gorillas all engaged in intentionally provocative behavior, frequently accompanied by characteristics of play.

They identified 18 distinct teasing behaviors. Many of the behaviors appeared to be used to provoke a response, or at least to attract the target’s attention.

Study senior author UCLA Professor Erica Cartmill said: “It was common for teasers to repeatedly wave or swing a body part or object in the middle of the target’s field of vision, hit or poke them, stare closely at their face, disrupt their movements, pull on their hair or perform other behaviors that were extremely difficult for the target to ignore."

Although playful teasing took many forms, the researchers noted that it differed from play in several ways.

Cartmill said: “Playful teasing in great apes is one-sided, very much coming from the teaser often throughout the entire interaction and rarely reciprocated.

“The animals also rarely use play signals like the primate ‘playface’, which is similar to what we would call a smile, or ‘hold’ gestures that signal their intent to play.”

The team found playful teasing mainly occurred when apes were relaxed, and shared similarities with behaviors in humans.

Dr. Laumer said: “Similar to teasing in children, ape playful teasing involves one-sided provocation, response waiting in which the teaser looks towards the target’s face directly after a teasing action, repetition, and elements of surprise."

The researchers noted that Jane Goodall and other field primatologists had mentioned similar behaviors happening in chimps many years ago, but the new study is the first to systematically study playful teasing.

Dr. Laumer said: “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."

She added: “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.”