By Stephen Beech via SWNS
Dogs’ ability to use facial expressions to convey emotions has been reduced by selective breeding, suggests a new study.
Changes in facial features as a result of breeding programs have constrained communication abilities in domestic dogs compared to wolves, say scientists.
The Durham University study found that the process of domestication and selective breeding has limited the ability of pet pooches to use facial expressions to convey emotions as effectively as their lupine ancestors.
Researchers used an extended ‘Dog Facial Action Coding System’ to analyze video recordings of captive wolves and domestic dogs during spontaneous social interactions and reactions to external stimuli.
The team identified nine distinct emotional states – including anger, anxiety, curiosity, fear, friendliness, happiness, interest, joy and surprise – that could be predicted based on wolves’ facial movements with 71 percent accuracy.
However, the accuracy rate dropped to 65 percent for domestic dogs across different breeds, according to the findings published in the journal Scientific Reports.
The confusion was especially high between positive states, such as friendliness, and negative states like fear, according to the research team.
They suggest that the varying facial “morphologies” resulting from selective breeding – such as shorter muzzles, floppy ears, pendulous lips and excessive wrinkling – have limited dogs’ ability to produce the same range of facial expressions as their wolf ancestors.
Study lead author Elana Hobkirk, a prospective PhD student, said: “This study demonstrates how important it is to be able to observe fine details in behavior, and how such observations have allowed us to see just how communicatively complex and sentient wolves are and how domestication may be affecting our social bonds with our companion dogs.”
Study co-author Dr. Sean Twiss added: “Our research team at Durham University focuses on individual differences in animal behavior, and Elana’s work adds an exciting new dimension to this, revealing how individuals differ in their abilities to convey their emotional states, and what that might imply for successful communication – or not – within social groups, including humans and their dogs.”
He said the findings indicate that traits such as “brachycephalic” – short and broad – skulls, floppy and semi-floppy ears, and pendulous lips were linked to nearly 80 percent of the cases where a dog’s facial expressions did not match the identified emotional state.
The researchers say confusion between positive and negative states could be detrimental to human-dog interactions – and even pose safety risks if people misinterpret fearful or aggressive behavior in dogs as friendliness.
Dr. Twiss added: “Successful communication of affective states is essential for highly social species as the study provides evidence that an unintended consequence of domestication is a reduced range of emotional expression in domestic dogs compared to wolves.”
The research team also suggested domestic dogs may “compensate” for limited facial expressions by vocalising more than wolves during social interactions.
