Why is yawning so contagious?

Funny Kitten GIF • Yawn is contagious. 2 kittens yawning one after another
Small kitten: “Hey little Bro, check this out” YAAAWN…”
Bigger kitten: “So what, I can do that too ” YAAAAAAWN...”
[Video: imgur.com]
#hashtag LiST (1,125)
   If you are looking for a, some, any PARTiCULAR Cat GIF among our 8,250 GIFs [100% SFW] you will find it/them via our #hashtag list with 1,125 entries 👀 ALPHAbetically sorted.
► #hashtag LiST ◄
Cat breeds & Cat's coat colors
▼ CATS by BREEDS ▼
Check out best cat pictures sorted by most popular breeds

▼ CATS by COAT COLORS ▼
Check out best cat pictures sorted by coat colors