By the cries of chimpanzees, people were able to recognize a situation in which there were animals, their level of arousal and how pleasant was the event. However, the participants managed to correctly identify the context only when they are asked simple questions with “Yes” and “no”, but not when I had to choose from ten options. The sounds that chimpanzees published in an unpleasant situation, determine going to be easier than signals of pleasure. Using acoustic analysis, the authors of the article published in the journal Proceedings of the Royal Society B: Biological Sciences, determined what sonic characteristics people recognize the cries of monkeys.
Charles Darwin suggestedthat vocalizations (e.g., cries, songs, meow and Moo) — an ancient evolutionary adaptation that allows animals to exchange information with relatives and with members of other species. Indeed, in the laughter of a man or the purr of a cat, we can determine (or at least assume) the emotional state of localizator. However, the attempt to anthropomorphisizing the behavior of animals can lead us to a dead end, and more reliable performance than the degree of satisfaction or dissatisfaction, are the excitation level and its sign (positive or negative), and behavioral context.
Previous experiments showedthat people can recognize the excitement and sign on the vocalizations of a number of animals: amphibians, reptiles and mammals. We can also consider the situation with some Pets sounds: maukau cats, barking dogs or squealing pigs. However, it is unknown how well people understand the vocalization of their close relatives, with whom we rarely meet in everyday life — human primates.
Scientists from Britain, Germany and the Netherlands under the leadership of Rosa Kamiloglu (Roza Kamiloğlu) from the University of Amsterdam conducted three experiments to understand whether people distinguish between arousal, his mark, and behavioral situation to the cry of the chimpanzee (Pan troglodytes). In the first test was attended by 310 volunteers, they were allowed to listen to 155 66 chimpanzee vocalizations that were recorded in ten contexts (e.g., when you attack the other chimpanzees, mating or separation from the mother). The participants had to choose which of the ten contexts is the sound and assess the level of excitation of the monkey and its sign on a five-point scale. “Correct answers” amounted to the Katie Slocombe (Katie Slocombe), an expert in the vocalizations of chimpanzees.
N+1 · Vocalization of chimpanzees, which tickled
N+1 · Vocalization of chimpanzees who found a lot of food
The task was too complicated: on average, volunteers are unable to identify any one of the behavioural contexts, but accuracy is significantly above random level determined the level of excitation of the chimpanzee and its sign (p < 0.001). Screams in the unpleasant monkeys a situation when strong excitation, the participants knew better than to pleasant (p < 0.001), this result agreed with the studies on the sounds of other animals. While the average level of excitation of people are better recognized for positive context. In General, volunteers are more inclined to hear the cries of animals negative emotions than positive.
In the second experiment (attended 3120 people) task simplified — participants had to choose one of the ten situations and the answer is “Yes” or “no” to the question “does this sound to the context X?”. Each volunteer kept asking about the same context; a quarter of the playing sounds concerned, and the rest were randomly taken from other situations (i.e., in 25% of cases the correct answer was “Yes”, otherwise “no”).
With a simplified wording of the question participants coped better and correctly recognize most of the sounds. For all four contexts, the proportion of correct answers was on average not higher than random level: when defining sounds, mating, separation from mother, tickling and frightened. The vocalization in an unpleasant situation, the volunteers were recognized better than positive contexts (p < 0.001).