SIMIAN SIMULACRA
Why monkeys succumb to pareidolia
A monkey was caught red-handed drinking petrol from parked motorbikes at the market in Panipat, in the northern Indian state of Haryana. Locals investigated after finding their fuel tanks empty. “The monkey was clearly addicted to the petrol,” said Gaurav Leekha. “It would refuse to eat even bananas and nuts if anyone offered it.” It was pulling out fuel lines and using them like straws. Metro, 10 Nov 2017.
Scientists at the University of York created a “chimpanzee jukebox” allowed the animals – 18 at Edinburgh Zoo and others at the National Centre for Chimpanzee Care in Texas – to listen to works by Mozart, Beethoven, Adele and Justin Bieber. While previous studies suggested that chimps found music relaxing, this 14week investigation found it had no effect on their behaviour, aggression or grooming habits. Indeed, it showed that they perceive all music as mere noise – although they cleared off quicker when fast pop music was played. “Music is not something relevant to them,” said Dr Emma Wallace, lead author of the report in the journal PLoS
One. “Music appreciation is possibly a uniquely human trait.” D.Mail, D.Telegraph, D.Mirror, 30 Mar 2017.
Monkeys, however, do seem to appreciate simulacra. To investigate whether pareidolia (perceiving a familiar pattern, typically a face, where none exists) was a uniquely human experience, Jessica Taubert at the US National Institute of Mental Health in Maryland and her colleagues trained five rhesus macaques to stare at pairs of photos. Each photo showed either an inanimate object that prompts pareidolia in humans, an equivalent object that doesn’t, or the face of a monkey. It was known that that both people and monkeys will look longer at images of faces than other things, so the team presented each of the photos in every possible pairing – 1,980 in all – and measured the time the monkeys spent looking at each.
The monkeys did indeed seem to succumb to pareidolia – they spent more time looking at illusory faces than the non-illusory photos they were paired with. They also spent more time looking at the illusory faces than the monkey faces, perhaps because they spent longer studying these more unusual “faces”, or because they tend to dislike holding the gaze of another monkey. Examining eye gaze patterns, the team found that the monkeys frequently fixated on the “eye” and “mouth” regions of the false faces, which is also how people behave when viewing real faces.
The human brain is primed to see faces from an early age. Babies can recognise a face while still in the womb – scans show that when dots of light are shone through the skin, foetuses preferentially turn to look at patterns that resemble faces, but ignore random shapes. Being able to quickly spot and interpret a face can give vital information about whether a social group is friendly or hostile. But sometimes we are too good at spotting faces, seeing the Virgin Mary in a damp stain. The fact that monkeys also easily per-