Dogs have been linked to humans and their ancestors for centuries. European and paleolithic dogs were first thought to have been linked around 15,000 years ago, while certain Asian domestication events were documented around 12,500 years ago. It’s safe to say that people have been keeping dogs as pets for a long, long time. But is it more nature than nurture? Sure, if you grow up with a family pet, you’re statistically more likely to own one in life later. But what made the connection at first? Is a person inclined to get a dog based on environmental factors, or is it biologically predetermined to happen?
A study was conducted to find out just that. Determined to discover the heritability of dog ownership, a pool of subjects were selected from the Swedish Twin Registry of all twins born between 1926 and 1996. Those applicants had to be alive in 2006. The final data set was comprised of 85,542 twins from 50,507 sets of twins. Information on those twins was again narrowed down to use only twins where information was available from both subjects in a twin pair, shrinking the study allotment to 35,035 pairs. Cross referencing dog ownership from 2001 and 2016 national dog registers, the researchers were able to see who had previously and who currently owned a dog at the time of the study.
Data was then predicted in relation to their genetics (heritability), common/shared environments, and uncommon/singularly experienced environments. The surveys conducted then produced the findings that heritability was very strong, about 57% in females, and 51% in males, meaning that throughout life, the twins had experienced differences in their settings, but the desire to own a dog was still very strong. Genetics then, are more predictive of dog ownership in adulthood than environment.
Obviously shared environmental factors were typically only comparable in early childhood experiences, thus leaving the researchers to believe that heritability was the cause for dog ownership, rather than environmental experiences.
While the study did not identify which specific genes led to the ownership of a dog, it’s an interesting case to consider. So the question remains to those of you reading this, was your companion chosen out of an environmental need, or one more biological?