Unlike humans and apes, rhesus monkeys don’t instantly recognise themselves in the mirror, but a report in the Cell Press journal, Current Biology, found this doesn’t mean the species can’t learn.
After two to five weeks of training, the monkeys had learned to touch face areas marked by a spot they couldn’t feel in front of a mirror.
When placed in front of mirrored video images, the monkeys also noticed virtual face marks on the video image, suggesting recognition of the image.
Most monkeys in the study (five out of seven) showed typical mirror-induced, self-directed behaviours, such as touching a mark on the face or ear.
They also used the mirrors in other ways that were unprompted by researchers to inspect other parts of the body. In previous studies, monkeys had not showed behaviour of self-recognition.
Neng Gong of the Chinese Academy of Sciences said: “Our findings suggest the monkey brain has the basic ‘hardware’ [for mirror self-recognition], but they need appropriate training to acquire the ‘software’ to achieve self-recognition.”