Dogs have a rich secret language that is only just being discovered, and research results shine more light on just how incredible our canines are.
You might be surprised to learn that the way your dog wags her tail, smells an object, or manipulates a toy is linked to her emotional state. Lateral bias is apparent when a human or animal shows a preference for one side of their body over the other, which is linked to the primary use of the left or right brain hemisphere.
Just as human favor one hand (and arm, leg, and foot) over the other, dogs tend to have a bias when it comes to using their paws. Watch your dog play with a toy and see if she favors one paw over the other. This is called paw preference, and most dogs favor using one paw over the other, while a minority show dexterity with both (called ambilateral in dogs), just like a person who is ambidextrous.
Evidence suggests that paw preference and the strength of that preference are closely linked with emotions and behavior. Dogs that favor the left paw more often use the right hemisphere of their brain, while right-pawed dogs have a more active left hemisphere, and this difference is reflected in their behavioral tendencies. These findings aren’t surprising, considering that the right brain hemisphere controls the left side of the body and the left hemisphere controls the right side of the body. The left hemisphere is activated when the brain is processing positive emotion such as happiness, excitement, attention, and affection, as well as something familiar; the right hemisphere takes over when the brain processes sadness, fear, and other negative emotions.
Various studies have shown that right-pawed dogs are less easily aroused and are better able to cop with novel environments and situations, whereas left-pawed dogs show more stranger-directed aggression than right-pawed or ambilateral dogs.1 Other studies have shown that dogs with no paw preference were more reactive to loud noises, whereas dogs with a strong paw preference were more confident and playful and less anxious or impulsive than dogs with weaker paw preferences…..2
Decoding the wag
Does your dog wag her tail more to the right or the left? The sweep and direction of the tail wag is an outward expression of emotion and reflects the way the two sides of the brain process information. Studies have shown that dogs wag their tails more to the right when greeting people they know and like, as well as unfamiliar people (if they are social dogs), although the tail wags lower. They wag their tails more to the left when seeing an unfamiliar dog.3 Again, the right tail wag is controlled by the left brain hemisphere, which is associated with more confident behaviors, while the left wag is controlled by the right brain hemisphere, associated with more cautious approach behaviors.
1Lara S. Batt, et al., “The Relationship Between Motor Lateralization, Salivary Cortisol Concentrations and Behavior in Dogs”, Journal of Veterinary Behavior 4, no. 6 (2009); 216-222; L. A. Schneider, P. H. Delfabbro, and N. R. Burns, “Temperament and Lateralization in the Domestic Dog (Canis familiaris)”, Journal of Veterinary Behavior: Clinical Application and Research 8, no. 3 (May-June 2013); 125-134.
2Batt, et al., “The Relationships” (2009).
3A. Quaranta, M. Siniscalchi, and G. Vallortigara, “Asymmetric Tail-Wagging Responses by Dogs to Different Emotive Stimuli”, Current Biology 17, no. 6 (2007); R199-201.
Excerpted from The Secret Language of Dogs – Unlocking the Canine Mind for a Happier Pet, by Victoria Stilwell; Ten Speed Press/Penguin Random House, Emeryville, CA; October 2016.