Chewbacca's Signature Star Wars Head Tilt Came More Out Of Necessity Than Choice
There are some interesting mysteries in the "Star Wars" franchise. For example, what the heck is M-Count? (It has to do with midi-chlorians, which are basically smart bacteria that can give you Force powers.) How did the Millennium Falcon make the Kessel Run in less than 12 parsecs when a parsec is a unit of measurement, not time? And why does Chewbacca tilt his head to the side so often, particularly when he hears something that might be confusing? It's a movement reminiscent of one that dogs make when they hear something interesting and are trying to parse it out, tilting their heads from side to side in curiosity, so one might think that's it. After all, Chewie even has the luscious locks of an Irish Setter and a nose reminiscent of a Pekingese, so it would make sense.
Sadly, Chewbacca actor Peter Mayhew died in 2019 at the age of 74, but before he passed away he shared a tiny tidbit about Chewie's classic head tilt, and it turns out there was a much more practical reason behind the movement than trying to mimic the character's more canine features. At a panel appearance at MegaCon in 2014, he told everyone assembled that the tilt had less to do with character design and more to do with being very, very tall.
A necessity, not a choice
At MegaCon in 2014 (via StarWars.com), Mayhew briefly explained that the maneuver was something that developed as a result of his constantly needing to duck in order to fit through doorways. Some of the doorways and passageways on various "Star Wars" sets are a little small by design, of course, but Mayhew probably had to duck through most doorways, given that he was a gargantuan seven feet, three inches tall. (For some context, former basketball player and entertainment personality Shaquille O'Neal, is seven-foot-one, a full two inches shorter.) When you're that tall, every doorway is a potential bonk to the head, whether it's built by the Empire, the Rebellion, or a bunch of furry little dudes on a forest moon.
Maybe Mayhew got so used to tilting his head to one side to get himself safely through doorways that he just instinctively did the tilt during other moments, like whenever he's listening to Han explain something. It's also possible that since Mayhew is usually looking at whoever's talking and they're guaranteed to be shorter than him he's trying to get his eyes slightly more on their level without looming over them. Whatever the reason, the result is that Chewbacca feels more truly alive.
One weirdly relatable Wookiee
There are quite a few characters in the "Star Wars" franchise that speak a language that isn't translated for the viewing audience, but none as central to the cast as Chewbacca (save maybe R2-D2, played by Kenny Baker in the original trilogy). Chewbacca grunts, growls, and roars in the primary Wookiee language of Shyriiwook, which isn't ever translated for us aside from Han Solo (Harrison Ford) occasionally explaining to those assembled who only speak Basic. That means that Mayhew had to communicate Chewie's feelings to the audience primarily through body language, and the signature head tilt is really the icing on the character-building cake, however unintentional it might have been. Being tall has its hazards, but at least it helped Mayhew perfectly play one seriously cool Wookiee.