Dog Wagging

What do you think of this new study about dogs wagging tails ? My feeling's  are haven't they got better things to study and spend money and time on 

I'm sure we all know when our dogs are happy sad or stressed , the warning sign for us with horses and dogs are ears up there fine,

ears back there not happy,

hair standing on the  back of a dogs neck that's look out

tail low and curled under there legs  there usually scared 

Wagging tail left or right there o k / happy 

Tail straight up and stiff cautious.

What' signs do your dog give you to let you know there happy or sad