#Articulated chimpanzee hand series#

Hewes further points out that comparative study of the vocal systems of primates and humans, both of their functions and of the neurological apparatus that controls them, has made it clear that the call systems of primates that have been regarded in earlier treatments as a possible substrate for the emergence of speech (e.g. Hewes suggests that it is plausible to suppose that this was a predominantly gestural form. Yet the evidence of burial practices, tool manufacture, and hunting among these people makes it highly likely that they were capable Sign Language Studies 9 of linguistic communication of some sort.

Hewes also refers to the work of Lieberman and his colleagues (see Lieberman 1973 for an overview) which suggests that the vocal tract of Neanderthal man was not suitable for the production of fully articulated speech. For example, they orient to and address behavior towards specific other individuals, they show certain limited amounts of gestural communication, and they can make use of each other's postures and incipient locomotory movements in gaining information from one another about the environment (Menzel 1971). He also points out that chimpanzees exhibit naturally much behavior that could be regarded as a substrate for gestural language. Hewes argues that the findings of the Gardners (1971), in which the chimpanzee Washoe has been shown capable of learning some elements of a gesture language, supports the contention that in terms of brain structure the pre-linguistic hominid would have had the cognitive capacity for a linguistic form of communication, even though it did not have the anatomical specializations suitable for speech. As Mayr (1968) has pointed out, behavioral change is always the first kind of change to take place in evolution-morphological change following later. The neurological and anatomical specializations associated with speech (Lenneberg 1967 Geschwind 1972) would have evolved only after the evolutionary shift in the direction of linguistic-like behavior. First he points out that language in its first form would have made use of such neurological and anatomical equipment as the prelinguistic hominid already had available to it. He adduces several different lines of evidence in support. Gordon Hewes (1973a) has revived the argument that speech is a late development in human evolution and that the first manifestations of a language capacity were in systems of gesture.

GESTICULATION, SPEECH, AND THE GESTURE THEORY OF LANGUAGE ORIGINS Adam Kendon The gesture theory of language origins. What's more, these asymmetries mirror those found in motor areas of humans, which suggests a common evolutionary origin, Hopkins says.In lieu of an abstract, here is a brief excerpt of the content: 6) that corresponded with their handedness. These chimps had somewhat lateralized brains ( Behavioral Neuroscience, Vol. When Hopkins looked at MRI scans of these chimps' brains, he found that there were asymmetries between the hemispheres, especially in two motor cortex areas, the precentral gyrus and the inferior frontal gyrus. It turned out that chimps were extremely right-handed for this behavior ( Journal of Comparative Psychology, Vol. So he and his colleagues introduced themselves to a variety of chimpanzees and recorded which hand each chimp used to throw feces at them. 'Chimps usually throw at new people-they'll often throw their at them,' Hopkins explains. In 2004, he designed an experiment to determine which hand chimps throw with. In 1998, Hopkins and his colleagues established that when making one-handed gestures, like pointing to something, chimps almost exclusively use their right hands.

#Articulated chimpanzee hand series#

A series of experiments in the '90s by Hopkins and others showed that movements requiring skilled coordination-the original research had chimps fishing peanut butter out of the end of a plastic pipe-were often done using the right hand, while the chimps were less preferential for unskilled movements such as simple reaching. But in the last decade, researchers have shown that other animals' brain hemispheres may be specialized for particular tasks.īill Hopkins, PhD, an Agnes Scott College primate researcher and biopsychologist, was one of the first to establish that, like humans, chimps tend to be right-handed, though not quite as ubiquitously as humans-about 70 percent. Historically, humans were the only animals thought to have handedness.