South Paw: Examining Paw Preference in Dogs and Connections to Human Handedness

By Bruce Porter

Hypothesis

It was hypothesized that most dogs would be right pawed because most humans are right handed and it was expected that this trend would also be found in dogs. It is believed that the dominant hand was determined by one’s genes, because most people have the same preferred hand as their parents. It is expected that the dogs will show a strong preference of paws throughout the trials. Test 3 (which is where the dog picks a treat from their preferred side) might show different results since it didn’t involve the use of paws. It is believed that regardless of the conditions of the test (i.e. whether or not the dog handler is on a different side), the paw preference of the dog will not be affected. Just like no matter what day, humans will always write with their preferred hand.

Materials

  • 10 dogs

  • Treats

  • Pencil

  • Paper

  • Ledge

Procedure

For each dog, the following were recorded: its age, gender, training level (high or low), whether or not it was spayed/neutered, reactivity to noises such as thunderstorms and fireworks,and its aggressiveness towards strangers.Four tests were then performed on each dog.

Test 1

The dogs were asked to sit and then to come. The foot they started moving with was recorded. This test was repeated 10 times and recorded each time to determine whether or not there was a trend in which paw went first.

Test 2

The dogs were asked to sit then lay down to determine which foot they initially extended to lay down. The test is repeated 10 times.

Test 3

The dogs were asked to lay down then a treat was placed on each side of it to see which side they took it from. This test was repeated 10 times.

Test 4

The dogs were asked to put their front paws on a ledge (a window sill, a couch, or a stool). It was observed which paw went up first. This test was repeated 10 times.

This whole procedure was repeated approximately one week later to gather more data, in order to show me how much of a preference these dogs really have for their right or left paws.

Observations

When comparing the results from each dog (Table 1), it was discovered that seven of the ten dogs had a paw preference, but the dogs without a paw preference all still had lateralization preferences. Test 3, which was not involving paws, was a very reliable test for lateralization since no dog switched sides between trials and no dog ever had 50%. Test 2 was also very reliable because no dog switched sides between trials and no dog ever got 50% either. Also, for all dogs except for Scout, the result of Test 2 was their overall preferred paw. It is possible that the dogs who didn’t appear to have a preference actually do have a preference based on the results of Test 2. Tests 1 and 4 were both very unreliable. In test 1, two of the dogs’ preferences switched between trials, and 4 of the trials had 50% results. In Test 4, three of the dogs’ preferences switched between trials, and 3 of the trials had 50% results. This could be due to the dog’s head position at the time. If the dog’s head is tilted to the right, they will lead with their left paw and vice versa. This is body mechanics and is used to balance out their bodies while running. (S.L. Prewitt).

Table 1. This table shows that some of the dogs changed preferences between their final paw preference and Test 2 (test 2 was a very reliable test).  These differences are shown in bold. This makes me wonder if their result for test 2 is the most accurate and should be their final paw preference. This chart also shows how a dog’s lateralization preference can be the opposite of their paw preference. These differences are shown in bold.

Table 1. This table shows that some of the dogs changed preferences between their final paw preference and Test 2 (test 2 was a very reliable test). These differences are shown in bold. This makes me wonder if their result for test 2 is the most accurate and should be their final paw preference. This chart also shows how a dog’s lateralization preference can be the opposite of their paw preference. These differences are shown in bold.

Table 2. Information and results summary chart.

Table 2. Information and results summary chart.

Discussion

How Dogs’ and People’s Handedness/ Pawedness is Decided

There are many different theories about how humans’ handedness is decided. There is evidence that handedness can be influenced by society and culture. For instance, teachers have been known to force children to switch from using their left hand to using their right hand for writing. Also, some more restrictive societies show less left-handedness in their populations than other more permissive societies. (Neal, 2016).

Language ability is split between the different hemispheres of the brain, much like handedness, which suggests that handedness became connected to language ability. For most, the parts of the brain that govern language are present in the left side of the brain these people tend to be right-handed. (Brandler et al., 2013).

The way that handedness is decided is through genes. (Corballis, 1997) The genetic proposal to explain hand preference states the following. There are 2 alleles of a gene, C and D, at the same genetic location. D, for dextral- right, C for chance. D is more frequent in the population and is more likely to occur. People with the C gene have a 50% chance of a left hand preference and a 50% chance of a right hand preference. People with C become amenablte to influences as stated earlier such as society and culture forcing kids to be right handed.

This type of research has not been as widely studied in other animals but may be the same in other animals. Although, since dogs are split half and half for paw preference it wouldn’t make sense that a dog’s preference is decided the same way because humans show 90% right hand tendencies. It’s possible that dogs have S and D genes, (S for Sinistral meaning left). It may be inductively inferenced that when 2 S genes combine it means left, when a D and S combine it is a half and half chance, and when 2 D genes combine it means right.

How Paw/Hand Preference Affects Behaviour

Some researchers have concluded that dogs with no paw preference are likely to be more reactive to noise such as thunderstorms and fireworks. (Branson & Rogers, 2006) Ambidextrous dogs are prone to experience intense emotional responses to a broad range of stimuli. Dogs with a preference are able to transfer their attention from these disturbing stimuli. This may support that ambidextrous people are more prone to PTSD.

As you’ve probably learned, the left hemisphere of the brain controls the right side of the body and vice versa. Also, the left side of the brain is proven to be the side that controls the positive thoughts and actions such as love, a feeling of attachment, safety, and calmness. The right side is in control of the negative thoughts and actions such as anger, fear, and aggression. (Since left handed people’s dominant hand is controlled by the right side of the brain, there is a connection that the right side of the brain also dominates the emotions. It has been found that there are many more left handed criminals in prisons than right, also in groups of people with emotional problems, there is a higher rate of left handed people. Although it may seem like there are few similarities between human and dog brains they are actually much more similar than we thought. Left pawed dogs have also been proven to have stronger responses to negative emotions. Left pawed dogs were way more aggressive to strangers than right pawed dogs in a study at the University of Adelaide in Australia. This study also found that ambidextrous dogs showed lower aggression scores. (Schneider, Delfabbro, Burns, 2013)

There are also many positive traits found in humans with left hand preference. Left handed people tend to be more creative, visual thinkers who excel in creative fields like art and music. They are also more likely to excel in ball sports and at tasks that involve three-dimensional thinking and hand-eye coordination. (Petplace.com, 2015).

This is only a generalization and many factors can affect dog and human behaviours such as past traumatic experiences, genetic factors, and health. In these studies, the researchers used the Canine Behavioral Assessment and Research Questionnaire. The dogs in this experiment were not tested with this questionnaire so there is no evidence that these findings are true in the subjects.

Conclusion

According to the data that was collected, three of the dogs are right pawed, four of the dogs are left pawed and three of the dogs are ambidextrous. This was surprising as it was believed that all the dogs would show a prominent paw preference. Other researchers found that the number of ambidextrous dogs was statistically insignificant and that almost every dog had a paw preference and the number of left pawed dogs is balanced with right pawed dogs. (Poyser, Caldwell, Cobb, 2006). If only the data from Test 2, which was the most reliable test for paw preference, is used, five dogs preferred their right paws, four preferred their left and one dog used both paws together. This is more similar to the results found in other studies. It was believed that the dogs’ preferences wouldn’t change between the two trials but it was found that many dogs did actually change their preference on some of the tests between the trials. This meant that these tests weren’t as reliable as others. Although, Doctor Jess Heath (Alpine Veterinary Clinic) said, “There are many ways to assess a dog for paw preference but no one can agree on the best way to test them. Dogs that show a preference for their right paw in one test might show a preference for their left paw in a different test. So if you had any data from your experiment that didn’t seem to make sense, you’re not alone in the world of dog paw researchers”.

There was some inconsistent correlation between dogs’ behaviour and paw preference between this experiment’s results and the results of other researchers. (Poyser, Caldwell, Cobb, 2006), (Branson & Rogers, 2006), (Schneider, Delfabbro, Burns, 2013). There are so many variables that affect a dog’s behaviour that it would be hard to draw conclusions from such a small test.

Dogs have been found to be similar to humans in many ways. Dogs and humans that are ambidextrous can both suffer from behavioural problems. (Branson & Rogers, 2006). Also, dogs and humans can both have an opposite paw preference than lateralization preference in other body parts. In one way humans are way different from every other animal. They are mostly right handed with only 10-12% being left handed. No other animal is known to have such a population preference. (Warren, 1980). One of the main reasons is because humans are the only animals that are culturally influenced to be right handed. There is also a genetic preference that reduces the probability of being left handed. (Corballis, 1997). This could be connected to how humans process language in their brains. Ninety five percent of right handed people have brains that process language mostly in the left hemisphere. This is more efficient than sharing tasks between both sides of the brain, which is what 80% of left handed and ambidextrous people’s brains do.

There are many things that could be investigated:

• Examine how paw preference is decided in dogs. This would allow for a comparison between dogs and humans to be done, and could lead to better understanding of the science behind this topic.

• Test many more dogs. This would give a larger population preference, which would make it easier to compare the results of this study to what other researchers have found.

• Do more repetitions of the tests. This would give more accurate and detailed results.

• Test the dogs to see if behavioural and paw preference correlations are true in them too. Knowing if paw preference and behaviour are connected is great information the public should know. When picking a dog, knowing if a left pawed dog is more likely to be aggressive for example, is very good to know. (Schneider, Delfabbro, Burns, 2013)

• Learn more about the history of cultural influences in handedness. This is a very interesting part of studying handedness, without these cultural influences humans population preference would be drastically different from what we see now.

• Find out why some tests were more reliable In order to conduct more tests, it is necessary to determine whether some tests are better so that the most accurate data could be collected.

• Determine if the top agility dogs in the world have a paw preference. This would be very cool to know and would help dog trainers pick the best dogs more easily. It would be less time and money consuming for trainers. Ambidextrous dogs can never be trained to the same level as dogs’ with strong paw preferences.

• Try the Kong test (putting treats in a Kong dog toy and observing which paw the dog uses to get the food out with) that is used in many paw preference studies. (Tomkins, Williams, Thomson, McGreevy, 2012). This test is used by many researchers, and thus is probably very reliable.

• Test an equal amount of male and female dogs. In this project, I did not test an equal amount of male and female dogs and this may have affected my results. If I tested both genders equally, I may have had different results.

To answer the question of this project: Yes, most dogs do have a paw preference, although not an overall population preference as humans have.

References

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About the Author

I am a grade 7 student from Golden Horn Elementary School in Whitehorse, Yukon Territory. In the winter I do Biathlon. I am participating in the 2018 South Slave Arctic Winter Games for Biathlon. In the Summer, I paddle with Flatwater Yukon. I love camping, fishing, hunting and hiking. I had an exceptional time at the CWSF 2018 and I am hoping to go again next year. I enjoy making interesting science fair projects that investigate things that are not commonly thought about. I love doing fun things with my dog such as agility and nose work. That is where my inspiration came from. If I can have fun with my dog whilst making an award-winning project, I’m in! I ended up winning a bronze medal at the CWSF! Science is very interesting and Science Fairs make it even more exciting!