Goats get a lot of love on the Internet. They get less in the pages of animal cognition journals.
The darlings of such research tend to be primates, whales, dolphins, dogs and horses. Goats, on the other hand, "are not considered to be the smartest cookies," said Christian Nawroth, an agricultural scientist at the Leibniz Institute for Farm Animal Biology in Germany.
But Nawroth knows otherwise. He uses words like "creative" and "attentive" to describe goats. And based on the results of his latest study, he insists hat the animals are also "complex."
Goat subjects Nawroth and colleagues worked with while at Queen Mary University of London had already shown themselves to be adept at reading subtle human body language. Now, the researchers have found, goats are also able to distinguish happy people faces from sad ones - and they prefer happy.
The results of the new study, which involved scientists observing how 20 goats reacted to pairs of black-and-white images of unfamiliar people displaying the two facial expressions, showed that goats "are even way more complex than we thought," said co-author Natalia Albuquerque, a doctoral student at the University of Sao Paolo.
The goats spent 50 percent more time approaching and nudging the happy-face photos, and in just over half of the trials, they interacted with the happy face first, said Nawroth, the study's lead author. They veered toward the angry one first in 30 percent; in the remainder they ignored both faces, he said.
"We humans are a very different species, and we express ourselves in a very different way - even our pupils are different," Albuquerque said. "If goats are sensitive to our facial expressions . . . that means that they possess very complex psychological abilities."
It also puts goats in rare company. Other animals, such as sheep, had shown that they could recognize human faces. But only dogs and horses had previously demonstrated an ability to differentiate between expressions. Whether the new finding means goats understand what emotion a human expression conveys is unknown - only dogs have proved capable of that - but it means they've at least got the first step in that process mastered, Albuquerque said.
It's significant because of the sort of domestication goats underwent, the authors said.
Unlike dogs and horses, which have lived in close contact with humans as companions and workers for thousands of years, goats were domesticated to produce meat, milk, skin and fur. It could be that as humans selected individual goats for tameness, an ability to distinguish human expressions came along with it, according to the study, published in Royal Society Open Science.
Or it could be that the goat participants of this study, all residents of the friendly face-filled Buttercups Sanctuary in southeast England, honed that skill. While some may have been abused by humans earlier in their lives, all those tested had resided at the sanctuary for at least a year, Nawroth said.
"They're in a really, really nice and fun environment," Albuquerque said. "The people are always bringing them dried pasta. That's their favorite food ever." (And it's why dried pasta was used in the training for the study's trials.)
But she said the Buttercups goats' experience with happy expressions doesn't make their performance in the study less interesting from a scientific perspective.
And that performance, she argues, should make people think. If goats see nuance in us, shouldn't we also see nuance in them?
"They probably feel, and they probably want certain things. But maybe this is also true for all the livestock species," Albuquerque said. "If we're showing that goats are more complex than we thought, maybe all nonhuman animals are more complex than we thought."