The researchers identified certain muscle features that help dogs look so cute, and it suggests that thousands of years of selective breeding have contributed to their ability to use expressions to their advantage.
"Dogs are unique from other mammals in their reciprocated bond with humans which can be demonstrated though mutual gaze, something we do not observe between humans and other domesticated mammals such as horses or cats," said study senior author Anne Burrows.
She is a professor at Duquesne University School of Health Sciences, in Pittsburgh.
"Our preliminary findings provide a deeper understanding of the role facial expressions play in dog-human interactions and communication," Burrows said in a news release from the American Association for Anatomy.
