Does the direction a dog's tail wags tell you more about their confidence?

Here's an unusual story that appeared in the Daily Mail online over the weekend; researchers at the University of Victoria, Canada claim to have found evidence that if a dog wags its tail predominantly to the left, it might be more confident in that situation than one wagging to the right.

The team used a robot dog-like model and tracked the behaviour of over 500 random dogs approaching the robot in a public park. Over half (56%) of those who wagged to the left approached the robot without hesitation, whereas only a fifth (21%) of those wagging to the right did the same. When they removed incidences where the owners might have influenced behaviour, the numbers changed to 41% and 28%, but still showed a marked difference.

Although the team stopped short of concluding whether it was an experience-driven or inherited trait, it did suggest some interesting consequences for training and communication with a dog. You can read more about that in the original article.

That got me wondering... have you ever noticed if your dog wags in a particular direction? Do they wag more in one direction than another in different situations? Obviously a really nervous dog won't wag at all, but do they change the direction of their wag if they're happy but a little hesitant? Having read the article I'm fascinated to know what dog owners think from watching their own four-legged friends interact with the world!

Since I have only cats at home, I can't observe for myself (reading a cat's tail is a whole other - equally complex and contentious - science I can tell you!).