Elke Zimmermann of the Institute of Zoology at the University of Veterinary Medicine Hannover knows the answer: "The laughter of humans is comparatively highly developed, but in its basic features it also exists with our closest relatives: the apes, " says Zimmermann. "Sounds from other animals sound like laughter to us". The neighing of the zebra, the cackling of the chickens or the "laughter" of the hyenas serves other functions in the intra-species communication, explains the behavioral scientist. "They are not like laughing in the human sense".
"If you want to look at laughter scientifically, you first have to define what distinguishes it, " emphasizes Zimmermann. It is a fundamental human emotional behavior, she emphasizes: From the Inuit, from the icy north to the Australian Aboriginal laughter, is an important expression of emotional communication in all forms of human culture. It is characterized by the same combination of body language and phonetic information: The corners of the mouth are pulled upwards, the teeth are shown, the eyes are closed a little so that the characteristic smile lines are visible. In parallel, staccato-like voices are produced. In this way, we can express happiness across cultures and defuse conflicts. Already babies at the age of four months, but also blind and deaf-born children can laugh, reports Zimmermann. Therefore, this vocal feeling is also considered an innate behavior of man.
The roots of laughter on the trail
How deep the laughter is rooted in the history of human development, the researcher and her team could prove by comparative studies on apes. The results indicate that laughter in basics was already part of the behavior of the common ancestor of the apes and humans, which presumably existed 10 to 16 million years ago. This was made clear by the comparison of vocalizations: All apes, including humans, react with a special treatment with laughter - a tickle attack.
The closer analysis revealed that the closer we are to a monkey species, the more similar the laughter sounds. "We have created a kind of salmon tree and this is in accordance with the molecular genetic family tree, " says Zimmermann. The special feature of human laughter is that it consists predominantly of voiced, melodic syllables, which are formed during exhalation. The laughter of the chimpanzees and bonobos, which are closest to us in terms of development history, also has such elements. Orangutan and gorilla, on the other hand, only laugh with voiceless giggles or peal sounds, as the investigations of the researchers showed. display
"Animal laugh" by body language
Laughter in the narrower sense is reserved for humans and their closest relatives. But if you extend the definition of laughter to an expression of joy, you can add more animal representatives. Humans express their joy not only through audible laughter: Often we only smile silently, we dance for joy or clap their hands. "You have to be careful and not interpret too much humanity into the behaviors of animals, " Zimmermann points out, "but behaviors that contradict moods that are similar to joy in humans are also quite common in some animals." Seen in this way, the fun-loving jumping of calves or the tail-waving of a happy dog is in a way a kind of laugh through body language.
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