In case you haven’t seen it, here’s the hysterical YouTube video of four pugs tilting their heads in unison (well, almost in unison) to various suggestions, spoken in the rising-pitch singsong fashion that we tend to use to speak to our canines.
After you’re done laughing, this may lead you to wonder: why does Mabel tilt her head in response to her human’s voice? It’s a phenomenon that has long intrigued dog lovers. In England back in the 1880s, for example, after fox terrier named Nipper’s human died, the dog was adopted by artist Francois Barraud. As Sharon Lynn Vanderlip recounts in her book, Fox Terriers: A Complete Owner’s Manual, Barraud observed Nipper’s habit of sitting in front of his phonograph and tilting his head in response to the sounds. The artist speculated that Nipper was waiting to hear his dead human companion. That inspired Barraud to create the famous painting “His Master’s Voice,” which later was adopted by RCA as its symbol.
Unfortunately, since Nipper never wrote his memoirs, we’ll never know what was actually going through his head as he sat in front of Barraud’s record player. (We can’t rule out the possibility that he was perplexed by the artist’s kitschy musical tastes.)
The explanations of the head tilt in canine behavioral texts seem to vary. In Alexandra Horowitz’s book Inside of a Dog: What Dogs See, Smell and Know, head-tilting is portrayed simply as an effort by dogs to adjust their pinnae, or outer ears, to focus upon the precise location of sounds. That’s something at which they’re actually not as good as humans, despite their ability to hear frequencies that we can’t detect. (By the way, here’s a basic primer on the anatomy of the canine ear.)
In contrast, Steven R. Lindsay’s Handbook of Applied Dog Behavior and Training sees the head tilt as a combination of physiological response and communication cues, which makes more sense to me. When a dog is listening to your voice, Lindsay writes, he or she is trying to identify familiar words and intonations that the dog has learned to associate with some activity (such as going for a walk or getting a treat). The muscles of the middle ear, which your dog uses to perceive such nuances of sound, are controlled by the nucleus ambiguus, a part of the brain stem that also controls facial expressions and head movements that are a part of canine communication. Neural control of the middle ear, he notes, works in synergy with facial expression, gaze, and vocalization. Ergo, Mabel the pug’s head tilt is simultaneously an effort by the dog to perceive what you’re saying, and a message to you that she is listening.
Lindsay also notes that “socially apprehensive” dogs generally don’t exhibit the head-tilt behavior. That may be why Kirby, my frenetic, frenzied puggle, doesn’t seem to tilt his head very much. In comparison, our more emotionally well-adjusted occasional guest pug, Tippy — whose human actually gave him that name because of his propensity for head-tilting — seems to hang on my every word. Maybe he’s more empathetic. Or maybe he’s just more determined to get a treat.