"Our findings indicate that people who are inexperienced in macaque behaviour have difficulties in recognising monkey's emotions, which can lead to dangerous situations where they think the monkeys are happy but instead they are threatening them," said Laetitia Marechal from University of Lincoln in the UK.
Researchers from University of Lincoln in the UK found that tourists made significant mistakes in interpreting macaques' emotions - such as believing a monkey was 'smiling' or 'blowing them kisses' when they were in fact displaying aggression - despite exposure to pictures designed to demonstrate what the animals' facial expressions mean.
Researchers quizzed three groups of participants - those with little to no experience of Barbary macaques, those with exposure to images of different monkey faces, and those who had worked with primates for at least two months - on what emotions were being portrayed in a series of images showing aggressive, distressed, friendly and neutral faces.
They found that all participants, regardless of their levels of experience, made some mistakes confusing aggressive faces with non-threating faces such as neutral or friendly faces.
The study was published in the journal PeerJ.