Primates have been teasing each other for 13 million years

Most human babies tease even before they say “mama.” This behavior is important because playful teasing is an important part of human interaction and development. Babies must have sufficient social intelligence to recognize and understand that their actions can mess up other people’s expectations of what will happen next.

[Related: The best science jokes to make you laugh, groan, and Google.]

Teasing can begin when human babies are eight months old, but we’re not the only primates capable of it. This foolish behavior has now been recorded in four different species of great apes. These basic forms of humor are thought to have evolved within the human lineage at least 13 million years ago. The findings are described in a study published February 13 in the journal Proceedings of the Royal Society B Biological Sciences.

“Great apes are good candidates for teasing because they are closely related to us, engage in social play, laugh, and display a relatively sophisticated understanding of the expectations of others,” study co-authors said Isabel Romer, a primatologist and cognitive biologist. She collaborated with the University of California, Los Angeles (UCLA) and the Max Planck Institute for Animal Behavior, she said in a statement.

Play and provocative non-compliance

Early teasing usually involves the toddler giving them some kind of surprise. Your baby can playfully offer the toy and take it back. Psychologists call this behavior provocative noncompliance. Developmentally, this indicates that your baby is beginning to understand that there are social rules and expectations that can be broken.

For the study, a team of scientists from research institutions in Germany and the United States observed orangutans, chimpanzees, bonobos, and gorillas in captivity. They analyzed spontaneous social interactions that appeared to be playful, mildly harassing, or provocative. The research team observed and recorded the teasing behavior, body movements, facial expressions, and the time it took for the teasing targets to respond. They also examine teasers by looking for evidence that the behavior was directed at a specific target, that the behavior is continuing or intensifying, and that the teaser was waiting for a response from the target. evaluated what the intention was.

All four species exhibited intentionally provocative behaviors, and these behaviors were often accompanied by play characteristics. The researchers identified 18 distinct teasing behaviors, including tickling, pecking, hair pulling, and hiding under objects. Many of these behaviors appeared to be used to get a response from the target, or at least to get the target’s attention.

“Teasers may repeatedly shake or brandish a body part or object in the target’s field of vision, hit or poke them, stare at their face, block their movements, pull their hair, or perform other actions. “It was very difficult for the target to ignore,” study co-author Erica Cartmill, an anthropologist and linguist at UCLA and Indiana University, said in a statement.

Primate’s “playful face”

Although playful teasing took many forms, it differed from typical play in several ways. According to the authors, great apes playfully tease in a more one-sided manner, where it often comes from teasing and is rarely reciprocated.

[Related: Adolescent chimpanzees might be less impulsive than human teens.]

“Animals also rarely use play cues, such as the primate ‘play face,’ which resembles what we call a smile, or the ‘hold’ gesture, which indicates intent to play,” Cartmill said. Stated.

The playful teasing of the apes mainly occurred when the monkeys were relaxed. Also, usually involving a one-sided provocation, the teaser stares into the target’s face and waits for a reaction. The authors note that although other researchers in the field, including primatologist Jane Goodall, described similar behavior in chimpanzees several years ago, this study is the first to systematically study playful teasing. It is pointed out that.

“From an evolutionary perspective, playful teasing exists in all four great apes, and the similarities between playful teasing and joking in human infants suggest that playful teasing and its cognitive preconditions are at least “This suggests that it may have been present in our last common ancestor 13 million years ago,” Raumer said.