Laughing is essential for people to connect. And, although the causes of laughter can vary between cultures and groups, the sound of a laugh is usually recognizable even among people who belong to different cultures. In addition, in people, laughter can express many different emotions: from positive feelings (such as fun) to negative feelings (such as nerves or stress). However, have you ever wondered if animals laugh?
According to the scientific community, many animals produce sounds during play that are similar to laughter. In fact, the researchers believe that these vocalizations could be a close analog to human laughter. For this reason, a group of scientists from the University of California (United States) has developed an investigation on the vocalization of animals during play.
Investigation Development
To carry out the study, the team selected 65 different species of animals that ‘laugh’ while playing. Most were mammals, although there were also some species of birds that have a characteristic laugh. Thus, according to the researchers, this study could help trace the evolutionary origins of human laughter.
Because some animals play as if they are fighting or hunting, they may make this sound to prevent the game from escalating and becoming aggressive. Also, according to Sasha Winker, lead author of the study, unlike real fights, play is often repetitive and occurs independently of other social behaviors, such as foraging or mating.
Some animals, such as macaques ( Macaca mulatta ) gasp silently while playing. Many other primates are also known to vocalize during play, as Winker claims. Therefore, the team of scientists wondered if laughter could be more widespread in animals than previously thought. To find out, they reviewed previous research looking for animals that vocalized during play. In this way, they were able to find a dozen examples: from primates and rodents to marine mammals.
Playful laughter among animals
Many of these sounds are only produced during play, such as the purr of a green monkey ( Chlorocebus aethiops ), the hiss and squawk of a bottlenose dolphin ( Tursiops truncatus ), and the screech of a squirrel monkey ( Saimiri sciureus ). Also, according to the study, most species of primates present a playful laugh: from gasps, clicks and grunts to laughs, trills and squeals. And while most of the animals that laugh are mammals, two species of birds (the Australian magpie and the kea parrot) also vocalize during play.
As for laughter in humans, according to the researchers, it originated during play. Human laughter could have evolved from a gasping sound that, over time, became the characteristic ‘ha ha ha’ we use today.
