Every pet ownÂer knows that aniÂmals love to play, but laughÂter seems reserved for humans, a few apes, and maybe a few birds good at mimÂicÂkÂing humans and apes. As it turns out, accordÂing to a new artiÂcle pubÂlished in the jourÂnal BioaÂcoustics, laughÂter has been “docÂuÂmentÂed in at least 65 species,” JesÂsiÂca Wolf writes at UCLA NewsÂroom. “That list includes a variÂety of priÂmates, domesÂtic cows and dogs, foxÂes, seals, and monÂgoosÂes, as well as three bird species, includÂing paraÂkeets and AusÂtralian magÂpies.” This is a far cry from just a few years ago when apes and rats were the “only known aniÂmals to get the gigÂgles,” as Liz LanÂgÂley wrote at NationÂal GeoÂgraphÂic in 2015.
Yes, rats laugh. How do sciÂenÂtists know this? They tickÂle them, of course, as you can see in the video just above. (Rat tickÂling, it turns out, is good for the aniÂmals’ well being.) The purÂpose of this experÂiÂment was to betÂter underÂstand human touch — and tickÂling, says study author Michael Brecht, “is one of the most poorÂly underÂstood forms of touch.”
LaughÂter, on the othÂer hand, seems someÂwhat betÂter underÂstood, even among species sepÂaÂratÂed from us by tens of milÂlions of years of evoÂluÂtion. In their recent artiÂcle, UCLA priÂmaÂtolÂoÂgist Sasha WinÂkler and UCLA proÂfesÂsor of comÂmuÂniÂcaÂtion Greg Bryant describe how “play vocalÂizaÂtions” sigÂnal non-aggresÂsion durÂing roughÂhousÂing. As WinÂkler puts it:
When we laugh, we are often proÂvidÂing inforÂmaÂtion to othÂers that we are havÂing fun and also invitÂing othÂers to join. Some scholÂars have sugÂgestÂed that this kind of vocal behavÂior is shared across many aniÂmals who play, and as such, laughÂter is our human verÂsion of an evoÂluÂtionÂarÂiÂly old vocal play sigÂnal.
GenÂerÂalÂly, humans are unlikeÂly to recÂogÂnize aniÂmal laughÂter as such or even perÂceive it at all. “Our review indiÂcates that vocal play sigÂnals are usuÂalÂly inconÂspicÂuÂous,” the authors write. Rats, for examÂple, make “ultraÂsonÂic vocalÂizaÂtions” beyond the range of human hearÂing. The play vocalÂizaÂtions of chimÂpanzees, on the othÂer hand, are much more simÂiÂlar to human laughÂter, “although there are some difÂferÂences,” WinÂkler notes in an interÂview. “Like, they vocalÂize in both the in-breath and out breath.”
Why study aniÂmal laughÂter? Beyond the inherÂent interÂest of the topÂic — an espeÂcialÂly joyÂful one for sciÂenÂtifÂic researchers — there’s the seriÂous busiÂness of underÂstandÂing how “human social comÂplexÂiÂty allowed laughÂter to evolve from a play-speÂcifÂic vocalÂizaÂtion into a sophisÂtiÂcatÂed pragÂmatÂic sigÂnal,” as WinÂkler and Bryant write. We use laughÂter to sigÂnal all kinds of intenÂtions, not all of them playÂful. But no matÂter how many uses humans find for the vocal sigÂnal, we can see in this new review artiÂcle how deeply non-aggresÂsive play is embedÂded throughÂout the aniÂmal world and in our evoÂluÂtionÂary hisÂtoÂry. Read “Play vocalÂiÂsaÂtions and human laughÂter: a comÂparÂaÂtive review” here.
RelatÂed ConÂtent:
Eye of the PanÂgolin: The Search for an AniÂmal on the Edge
DownÂload AniÂmals and Ethics 101: ThinkÂing CritÂiÂcalÂly About AniÂmal Rights (Free)
Josh Jones is a writer and musiÂcian based in Durham, NC. FolÂlow him at @jdmagness
So what you’re sayÂing is: Cats don’t laugh?
What does it sound like with dogs? Do they actuÂalÂly “laugh” out loud or someÂthing else.