Researchers at the Charite University of Medicine in Germany have carried out the study and found that chimps link sounds and levels of brightness something akin to synaesthesia in people.
Such an association could help explain how our early ancestors took the first vital step from ape-like grunts to a proper vocabulary, the ‘New Scientist’ reported.
Synaesthetes make unusual connections between different senses, they might sense cert -ain tastes when they hear mus- ic, or “see” numbers as colours.
The researchers, led by Vera Ludwig, have shown for the first time that chimpanzees also make cross-sensory associations.
The team repeatedly flashed black or white squares for 200 milliseconds at a time on screens in front of six chimpanzees and 33 humans.
They had to indicate whether the square was black or white by touching a button of the right colour.
A high or low sound was randomly played in the background during the test.
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.
But performance was poor for humans and lower for chimps’ when the sounds and colours were swapped.