[Animals] At least 65 animal species laugh like humans, study finds

[#Steeven.™]

Researchers at the University of California, Los Angeles (UCLA) analyzed vocal records from animals that could be similar to human laughter.

Laughter is an expression of happiness and joy that can help us feel better; but, apparently, we would not be the only species on Earth that manifests this emotion.

According to research carried out by a team from the University of California, Los Angeles (UCLA), in the United States, at least 65 animals can laugh like humans.

In an article published in the journal Bioacoustics by Sasha Winkler, an anthropologist, and Greg Bryant, a UCLA communication researcher, the authors take a closer look at the phenomenon of laughter throughout the animal kingdom.

The researchers reviewed the existing scientific literature on animal play behavior, looking for mentions of vocal play cues, or what could be considered laughter.

They found that this vocal play behavior is documented in at least 65 species. That list includes a variety of primates, cows, domestic dogs, foxes, and seals, as well as three species of birds, including parakeets and Australian magpies.

"This work very well exposes how a phenomenon once thought to be particularly human turns out to be closely related to behavior shared with species separated from humans by tens of millions of years," Bryant said.

In their study, the researchers looked for information on whether the recorded vocalizations were high or low, short or long, high or low, loud or tonal, and formed by a single call or a rhythmic pattern.

They then set out to determine if these known characteristics of the game sounds matched up.

Such vocalizations are believed to help emphasize the non-aggressive nature of the game, a necessary function in the animal kingdom, in which much of the game takes the form of rough and tumble activities and mock fighting.

According to the team, much has been documented in the scientific literature on other characteristics of play behavior in animals, including aspects of body language such as the 'playing position' (front legs on the ground and rear raised) made by dogs and the "play faces" seen in primates.

“When we laugh, we often provide information to others that we are having fun and we also invite others to join in,” Winkler said. "Some scholars have suggested that this type of vocal behavior is shared among many animals that play, and as such, laughter is our human version of an evolutionarily ancient vocal game cue."

While Winkler and Bryant say that further observation and research on vocalizations would be fruitful, they also note that such observations can be difficult to achieve in the wild, especially for animals whose play sounds may be quieter.

Paying attention to other species in this way sheds light on the form and function of human laughter, the researchers write, and helps us better understand the evolution of human social behavior.