Evolutionary origins of our giggles, laughs and tickles

If you’ve ever laughed uncontrollably while being tickled, you may have your DNA to thank. A growing list of our fellow primates seem to laugh, or at least have “tickle-induced vocalizations,” implying it’s a trait we’ve all inherited from a common ancestor. In fact, as more research on the topic is conducted, it seems that there might be more mammals out there that giggle, assuming we learn to recognize it.

Studies have been done on orangutan, gorilla and chimpanzee infants and juveniles, and they’ve all been found to laugh when tickled. However, these “vocalizations” don’t seem to be limited to crude physical responses to skin sensations. Chimpanzees have been found to use varying degrees of smiles to express their happiness, including silent “laugh faces,” indicating their appreciation of something fun or funny without a full guffaw. Koko the signing gorilla also shows degrees of sophistication in her expressions— laughing at awkward, clumsy movements by others, like we laugh at Laurel & Hardy, contrasted with a different laugh altogether when she’s excited about good news.

Sharing the fun

So is laughter simply a primate communication tool? It looks like it may have a farther reach than that. Rats have been found to enjoy being tickled enough that they’ll pursue the hand that tickled them. They giggle too, although this was only discovered after recorded sounds were shifted to a frequency low enough for our ears. But that discovery hints that there may be other tickle-me-mammals out there, and that we just haven’t known what exactly to look for.

New laughing species may also change the scope of why anyone is laughing in the first place. Being ticklish may actually be connected to play as a form of social learning, and laughter as communication then built on that foundation.

Source: Do Animals Laugh? Tickle Experiments Suggest They Do by Liz Langley, Weird and Wild