Left Pawed or Right Pawed: Do Dogs Show a Preference?
One out of ten humans is left-handed, but what about man’s best friend?
Posted Feb 11, 2019
Everyone knows someone who is left-handed—statistically speaking, about one out of ten humans prefers to use the left hand for skilled motor activities like writing a note or drawing a sketch. But what about animals? Do they also show handedness? Until the 1980s, researchers thought that handedness was something typically human that only a few, if any, other species showed. However, more recent research suggests that this idea was wrong. For example, a 2013 study comparing handedness in 119 different animal species ranging from toads and lizards to birds and primates found that 51% of the investigated species preferred one limb over the other when doing a fine motor task (Ströckens et al., 2013).
One of the most extensively investigated species of all is, unsurprisingly, dogs. Several studies have been conducted on handedness (or rather, "pawedness") in dogs, but the results are somewhat inconclusive between studies. Some find that dogs are right-pawed, others report that they are left-pawed, and yet others fail to find any preference at all. This puzzling pattern is not uncommon in animal research, as individual studies tend to test only a few animals rather than rely on large cohorts. To solve this problem, we recently conducted a so-called meta-analysis of paw preference in dogs, i.e., a statistical integration of different empirical studies (Ocklenburg et al., 2019).
Overall, 23 different studies with more than 1300 individual dogs altogether were analyzed. The result? Dogs show paw preference, but it is somewhat different to human handedness. Overall, 63% of animals showed a preference for one paw, while 37% did not. This number is much larger than in humans, where only about 1% of people are really ambidextrous. In a second analysis, we wanted to know whether dogs, like humans, on average show a preference for the right side. This analysis clearly indicated that that was not the case; dogs without a preference were the largest group (37%), followed by dogs that showed a rightward preference (32%), and dogs that showed a leftward preference (31%). Thus, dogs have almost the same chances for being left- or right-pawed, or having no paw preference at all.
This yields an interesting question. If you wanted to know your dog’s paw preference, how would you determine it? In humans, handedness is often determined by asking people which hand they use to write, draw, or perform other skilled activities, but dogs rarely write letters or draw pictures. One task commonly used by researchers is the so-called food reaching task, and it is easy to try this test out at home! For example, in one recent study on paw preferences in dogs (Wells et al., 2017), the scientists used a hollow, canonical shaped rubber toy that moves around erratically when pushed, similar products can be bought at pet stores or online. The toy had a large opening on one side that was filled with moist dog food and was then given to the dogs to play with. The researchers assessed which paw the dogs used to hold down the toy when they licked the food out of the toy. The idea was that the dogs would use their more skilled paw to hold down the toy, which could move unpredictably due to its shape. Each animal was tested until at least one hundred paw uses were recorded, and the number of times the left paw was used was compared to the number of times the right paw was used to determine individual paw preference. While obviously not following the strict standards of scientific experiments, a similar set-up can easily be used at home to get a good guess whether Rex is a lefty or a righty.
Ocklenburg S, Sevim I, Peterburs J & Papadatou-Pastou M. (2019). Paw preferences in cats and dogs: Meta-analysis. Laterality, in press.
Ströckens F, Güntürkün O, Ocklenburg S. (2013). Limb preferences in non-human vertebrates. Laterality, 18, 536-575.
Wells DL, Hepper PG, Milligan ADS, Barnard S. (2017). Cognitive bias and paw preference in the domestic dog (Canis familiaris). J Comp Psychol, 131, 317-325.