American sitcoms use the effect in a targeted manner: laughter is shown in order to convey the fun even more intensely to the television viewers and to encourage them to laugh. In addition, many other examples illustrate: For humans, it is typical to pick up the emotional signals of others - laughter, smiles and giggles are definitely contagious.
But can animals laugh as well? Analytically speaking, the answer is yes: in some highly developed mammals, certain signals correspond to our "Ha-Ha" - communicative signs of positive mood, as well as laughter. Studies have already shown that these signals are also contagious. Chimpanzees and rats, for example, can be animated by the joyous signals of their conspecifics to a similar mood. The researchers around Raoul Schwing from the University of Veterinary Medicine in Vienna have now demonstrated this effect for the first time in a bird species - the Kea (Nestor notabilis).
Special sounds correspond to our laughter
The extensive vocalisation repertoire of these parrots birds aroused the researchers' suspicion that they could have similar principles to laughter. Not only do keas have amazing cognitive abilities, such as dealing with objects, but also complex gameplay. "They emit special sounds, which we have analyzed in detail, " says Schwing.
To investigate the effect of these game sounds, he and his colleagues recorded some of these calls for some five minutes to some wild Keas in New Zealand and watched their reactions. As a control served other vocalizations of the parrot birds, as well as the song of the South Island robin. display
When Keas "laugh" ...
It turned out that only the special play sounds caused a keas' emotional response: "If we played them the special ringing that we could identify as play sounds, then they either animated other non-playing keas or dealt with an object or specific alone Flight maneuvers ", reports Schwing. Therefore, the call of the mountain parrots does not seem to be a simple invitation to play, but rather triggers basically game behavior, the researchers conclude.
They come to the conclusion: The Keas reacted to the "fun sounds" emitted by conspecifics with an independent, emotional reaction. According to the researchers, these sounds can be compared to human laughter and thus it is clear that laughter is contagious even with the kea.
Original work of the researchers:
- Current Biology, doi: 10.1016 / j.cub.2017.02.020