A dog wagging its tail has long been associated with an expression of happiness and joy on part of the dog. Apparently there is more to the wag of its tail than its owner knew about. At least that’s what the researchers at the University of Trento claim to have found under the guidance of neuro-scientist Giorgio Vallortigara.

In an experiment conducted at the University the research team was astonished to find that when viewed in slow motion the wagging of a dog’s tail leans more to one side or the other of the body. Closer examination of the back and forth wagging brought the fact into attention that when a dog is simply excited to see its owner, or a friendly dog teh tail was likely to lean more to the right side of the body.

If the dog was wagging with its tail leaning more towards the left side of the body he was often nervous, and was perceiving the person before him or strange dog as a potential threat. Vallortigara said that the change in movements were a result of cognitive asymmetry, where one side of the brain controls the other side of the body.  One thing this science project brought to the fore was that by watching a dog carefully you can decipher its mood based on a few flicks of its tail.