I found out something about my dog, and your dog too.

Dogs' behaviour - it's all in the wag

Dogs wag their tails to the right when they see something familiar, such as their owner, and to the left when confronted with something they want to run away from, it was revealed yesterday. The bias is subtle, requiring video analysis to spot, and not obvious enough for you to tell whether the next dog you meet is going to lick your face or turn tail.

But, researchers suggest, the study of wagging could be used in animal welfare to help vets to gauge an animal's state of mind.

Shown a human, tails wagged consistently to the right. They carefully studied the tail wagging angle and ignored twitches of less than three degrees overall, "which were plausibly not correlated to wagging".

They found that the unfamiliar person elicited less wagging than the owner, and the cat the least wagging of all, though still slightly to the right - probably because the dog was so keen to give chase that it was distracted.

Shown a large, unfamiliar and intimidating dog, the dogs wagged their tails more to the left.