"Chimp Brains may be Hard-wired to Evolve Language"

The following clip shows an experiment conducted by Vera Ludwig at the Charite University of Medicine in Berlin, Germany.  In the experiment, human and chimps were asked to identify the color of a square which flashed on the screen by touching the button of the corresponding color.

But why is this experiment important?

The experiment shown above tests synaesthesia or the involuntary connections between senses.  For instance, in humans one might "sense certain tastes when they hear music" (New Scientist).  During the study, high or low background pitches were played in the background as the experiment was conducted.  Interestingly, the results indicated that the subjects' ability to quickly and correctly identify the correct color being displayed was effected by the pitch played.  "Chimps and humans were better at identifying white squares when they heard a high-pitched sound, and more likely to correctly identify dark squares when played a low-pitched sound" (New Scientist).  

This finding is important because "cross-sensory associations" are present in both chimpanzees and humans.  Thus, this trait must have evolved very early on in a common ancestor.  In addition, "cross-sensory associations" may be linked to the development of speech and language.  By associating different pitches with different types of objects (such as associating high pitches with light colored objects) this ability would have made it easier for human ancestors to create a common vocabulary.  Consequently, though synaesthesia alone did not lead to the evolution of language, understanding when this trait arose may help us to better understand the development of speech. 

http://www.newscientist.com/article/dn21242-brains-wired-for-language-if-only-chimps-could-talk.html