WHY DO MOST HUMANS HAVE POSITIVE FEELINGS FOR DOGS?

Dogs occupy a unique place in human hearts compared to our relationships with other animal species. Scientific research indicates that dogs were the first animals to be domesticated by humans. Paleontological evidence suggests this process began between 14,000 and 17,000 years ago, with genetic studies hinting that domestication might have started even earlier.

Thanks to this long history with humans, dogs are the most widely spread animal species in the world, found in nearly every area where people live. They are the most commonly kept companion animals, and the deep affection people feel for dogs is reflected in the countless books, stories, and websites dedicated to them. But this raises an intriguing question: Why? What makes our bond with dogs so extraordinary?

Why Should We Like Dogs?

Psychologists believe that attitudes toward dogs and dog ownership—whether positive or negative—are shaped by culture, social influences, and historical context. For instance, certain religions or cultures may either embrace or discourage interactions with dogs, which can, in turn, influence an individual’s personal experiences and views. Research supports this, showing that exposure to dogs during childhood is linked to more positive attitudes toward them and a higher likelihood of owning a dog in adulthood. However, there may be more at play.

When a person, particularly a child, encounters a non-threatening dog for the first time, they typically approach and attempt to interact with it. This contrasts sharply with initial encounters with animals like snakes or spiders, which are often met with fear or disgust, leading people to avoid them—even if they have never seen them before. Could such responses be rooted in our genetics?

The Personality Factor

Research suggests that an individual’s personality plays a key role in determining whether they become a dog owner, a cat owner, or choose not to own pets at all. Studies from the University of Texas at Austin and the University of Florida, for instance, found that people who are more extroverted, sociable, and low in neuroticism are more likely to own dogs. In contrast, cat owners tended to be more solitary, reserved, and somewhat more neurotic. This aligns with the findings of a study I conducted with over 6,000 participants, which revealed that a person’s personality not only predicted their affinity for dogs but also influenced their preference for specific breeds.

These findings are significant because there is substantial evidence suggesting that genetic factors play a major role in shaping our personality. For instance, estimates show that approximately 53% of extraversion, 41% of neuroticism, and 42% of agreeableness can be attributed to hereditary influences. Given this genetic basis for personality traits, and the fact that personality is linked to attitudes toward dogs, it’s only natural to consider whether there may be a genetic component influencing whether a person is drawn to dogs and wants to own one.

A Large Twin Study

Building on this reasoning, Swedish researchers led by Tove Fall at Uppsala University utilized some unique data resources available in Sweden to test this hypothesis. Her team had access to the Swedish Twin Registry, which, founded in the late 1950s, contains information on all twins born in Sweden. Additionally, since 2001, national data on dog ownership has been available through two dog registries, along with a legal requirement for all dogs in Sweden to be registered.

To determine if genetics influence dog ownership, the most straightforward approach is to study twins. There are two types of twins: identical and fraternal. Identical twins occur when a single egg is fertilized by a single sperm and then splits into two individuals during the early stages of development. These twins share the same genetic makeup, making them genetically identical. As a result, they are the same sex, look alike, and share all genetically determined traits.

Fraternal twins, on the other hand, are the result of two separate eggs being fertilized by two different sperm cells. These twins share about 50% of their genetic material, similar to regular siblings, and may not resemble each other or share the same sex.

Both types of twins typically grow up in the same family, sharing the same environment, culture, and parenting influences. If we observe more similarity in behaviour between identical twins—who share all their genes—than between fraternal twins, who share only half of their genes, it would suggest a genetic influence on that behaviour.

For their study, the researchers examined 35,035 pairs of twins, determining whether they were identical or fraternal and whether they had become dog owners. If genetics played a role, the concordance rate (the likelihood that both twins either owned dogs or both did not) should be higher in identical twins. The study found that identical twins showed higher concordance than fraternal twins, suggesting that genetic factors are likely influencing dog ownership.

How Much of Our Feelings for Dogs Is Genetic?

After conducting extensive statistical analysis using structural equations, the researchers estimated that the genetic component influencing our inclination to own a dog accounts for 57% in females and 51% in males. This means that approximately half of the psychological drive to own, or not own, a dog is shaped by our genetics, with the other half influenced by environmental factors like personal experiences and culture.

The conclusion is clear: a significant portion of our affection for dogs may stem from our genetic heritage. This bond likely developed through a process known as co-evolution, where two species influence each other’s evolutionary paths due to prolonged social interaction. According to research from Washington State University, this process began thousands of years ago when dogs and humans started living, hunting, and defending one another. Over time, this mutual relationship became embedded in our genetic makeup.