In the study which was carried out at the Buttercups Sanctuary for Goats in Kent, the researchers found that the goats spent more time examining the smiling faces with their snouts before looking at the angry photos.
About 52 percent of the goats studied went to the happy face and about 30 percent first looked at the angry faces and some didn't choose either expression. Before animals were hung two portraits - people with good and bad facial expression.
Scientists have found that goats are drawn to humans with happy facial expressions.
It implies that it is not just companion animals, such as dogs and horses, that have an ability to perceive facial cues.
"There are hundreds of millions of these animals and they deserve to get the best possible care that we can give them", lead researcher Alan McElligott, professor at University of Roehampton, told ABC News.
The authors concluded that "goats can distinguish between happy and angry images of the same person, indicating that they can visually differentiate human faces conveying different emotional valences".
The researchers believe their work has implications for understanding how animals process human emotions and facial cues. Indeed, the trial including sets of smiling and frowning faces, when done on horses, has demonstrated that horses physiologically respond to photographs of angry human faces with elevated pulses and different indications of stress.
The study of emotion perception has already revealed complex capabilities in dogs and horses, says co-author Natalia Albuquerque, from the University of Sao Paulo. "Our results open new paths to understanding the emotional lives of all domestic animals".
So his experiment was motivated by this belief that people have underestimated the "cognitive ability of livestock - cows, sheep and pigs and goats".
If you want to make friends with a goat, then stitch on a smile, turn that frown upside down ... and keep to their right.
With almost 1 billion goats in the world, McElligott wants to make people realize the benefit of treating them nicely. "These aren't "dumb" animals", he said.
Scientists suggest that domestication may have influenced the subjective capacities of farm animals more than we've beforehand suspected.