Sheep are about as capable of recognizing faces as monkeys or humans, University of Cambridge researchers report Tuesday in the journal Royal Society Open Science.
The average sheep has always been judged a placid and dim-witted creature, a view epitomised by Sir Winston Churchill when he labelled Clement Attlee a "sheep in sheep's clothing".
Initially, the sheep were trained to approach certain images by being given food rewards.
It had been known that sheep can recognize familiar faces of other sheep and of humans.
"Humans do tend to underestimate the ability of sheep", Morton said by email.More news: Mike Evans suspended one game for cheap shot on Marshon Lattimore
Next, the sheep were taken into the barn and shown two photos.
The research's lead author Prof Jenny Morton said, "What we did is ask whether a sheep could learn to recognise someone from a photograph".
"We've shown with our study that sheep have advanced face-recognition abilities, comparable with those of humans and monkeys". "Although I didn't think sheep could recognize emotion, it made me think about face recognition as a complex brain process".
Recognizing human faces is a skill you may take for granted-but you're also a human.
If you ever find yourself in the company of sheep, don't be surprised if they seem to recognize you. But there are at least eight sheep who can recognize the former president by his face. Training involved the sheep making decisions as they moved around a specially-designed pen. One was a celebrity it had seen before, and one was a photo of a non-celebrity who looked similar and had the same gender and ethnicity. If they chose the wrong photograph, a buzzer would sound and they would receive no reward. "Sheep successfully recognized the four celebrity faces from tilted images". In these initial tests, the sheep were shown the faces from the front, but to test how well they recognised the faces, the researchers next showed them the faces at an angle.
To challenge the sheep even further, scientists showed them the same celebrities in photos captured from a different, tilted angle.