i share my life with 2 labrador mixes. the oldest one of them is 7 years old, since he has been aprox. 6 month old he gave his human pack members a big smile when he welcomed them back home. his mouth is open one can see all his teeth, his nose is wrinkled. closes his mouth and repeats showing teeth that in a fast repetiton. of couse it was clear he is laughing, smiling !! about 2 years ago there has been made a scienifical research about this behaviour in dogs (dr. fedderson-peterson). my dog and i participated in this project, ended up on t.v. with that beautiful smile. so i did my own little research..... both my dogs imitate me nodding the head, sticking out their tongue just a tiny bit, winking with one eye, licking their lips, showing their teeth. NO CLICKER TRICKS!!! dogs are wonderful creatures but to my surprise: i have not read anything in english literatur about the ability of dog to imitate us or that adapted behavour.
