It has long been established that monkeys enjoy games. But to what extent can their playful pleasure compare with that of humans? An international team of cognitive biologists and primatologists has now revealed the presence of playful teasing across all four great ape species: orangutans, chimpanzees, bonobos, and gorillas. Their assessment of the teasing's intentionality was supported by evidence showing the behavior targeted specific individuals and persisted as the teaser awaited a response.
Similarities with teasing in human babies up to the age of 8 months, before speech, have been observed. This differs from play and can be seen as a cognitive precursor to joking, according to the authors of the study published in the February 14 issue of Proceedings of the Royal Society B. They conclude that it is likely that the cognitive prerequisites for joking, unique to humans, may have been present in our last common ancestor, at least 13 million years ago.
"Joking is an important part of human interaction, one that draws on social intelligence, an ability to anticipate future actions and an ability to recognize and appreciate the violation of others' expectation," reads the study, whose first signatory, Isabelle Laumer, is a postdoctoral researcher in primatology and cognitive biology at the Max Planck Institute of Animal Behavior, who worked with researchers in anthropology and cognitive science at the University of California, Los Angeles, and San Diego.
The first forms of teasing in humans appear even before infants produce their first words, starting as young as 8 months old. This can take the form of repeated provocations, often involving surprise. Infants tease their parents by offering and withdrawing objects, enjoying the reactions they provoke.
If in their study, researchers have identified 18 distinct teasing behaviors exhibited by the great apes under examination, in the realm of human humor, the art of joking knows no bounds.