The American research duo now observed two chimpanzee and bonobo groups each with a total of 47 animals. The biologists divided the hand and foot marks and the facial and sound signals into several classes and examined in which situation and with which purpose the monkeys used a certain sign. The researchers found that facial expressions and vocal sounds are strongly linked to their context and thus have approximately the same significance in both species. On the other hand, the monkeys used their hands and feet very flexibly, and the signals even differed between the groups of the same kind. The same hand gesture could therefore mean something completely different in another situation or within another group, while a scream, for example, always responded to a Attack or a threat, the scientists explain.
Interestingly, bonobos received a more frequent response from their peers when mimicking facial expressions, gestures, and vocal sounds, rarely using such combined signals. The miniature chimpanzees are likely to use the respective means of communication deliberately, rather than simply merge them rashly, the researchers said. The communication between bonobos is therefore likely to better characterize the communication between man's early ancestors, the scientists speculate. They now hope to be able to draw conclusions from the results on the origin of language in humans.Amy Pollick & Frans de Waal (Emory University, Atlanta): PNAS, online pre-release, DOI: 10.1073 / pnas.0702624104 ddp / science.de? Claudia Hilbert ad