The process of domestication and selective breeding in dogs has limited their ability to use facial expressions compared to wolves, according to a study published in Nature’s Scientific Reports.
In this study, a Durham University, UK team used an extended Dog Facial Action Coding System to analyse video recordings of wolves and dogs during social interactions and reactions to stimuli. The authors identified nine emotions based on facial movements: anger, anxiety, curiosity, fear, friendliness, happiness, interest, joy, and surprise. For the wolves, these emotions would be predicted with 71% accuracy, but this value dropped to 65% for dogs. The confusion was particularly high between positive emotions, such as friendliness, and negative emotions, such as fear. The authors highlight how this confusion could be detrimental during human interactions and even dangerous if humans misinterpret fearful or aggressive behavior in dogs as friendliness.
The team suggests that morphological changes caused by selective breeding, including shorter muzzles, floppy ears, and excessive wrinkling, limit dog’s abilities to produce the same range of facial expressions as their wolf ancestors.
“This study demonstrates how important it is to be able to observe fine details in behaviour 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,” said Elana Hobkirk, from Durham University’s Department of Biosciences.
“Our research team at Durham University focuses on individual differences in animal behaviour, 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,” added Dr. Sean Twiss also from Durham University.
The researchers suggest domestic dogs may compensate for limited facial expressions by vocalising more than wolves during social interactions.
Hobkirk ER, Twiss SD. Domestication constrains the ability of dogs to convey emotions via facial expressions in comparison to their wolf ancestors. Sci Rep. 2024 May 7;14(1):10491. doi: 10.1038/s41598-024-61110-6