A scientific paper published in Vet Record in 2002 found that dogs reared in domestic environments and/or exposed to urban environments had fewer problems with aggression to strangers and avoidance behaviors.
The researchers (Appleby, Bradshaw, and Casey) looked at 820 cases of dogs that were referred to a veterinarian for aggression or avoidance/apprehension concerns between 1996 and 1999 compared to 123 dogs with no reported behavioral problems or behavioral problems like excitability, chewing/destruction, or pulling on the leash.
The researchers looked at several factors:
- Maternal environment. The dogs were categorized into being reared in domestic (inside the home) versus non-domestic environments (kennels, barns, garages, outdoors).
- Age of acquisition. The owners also reported when the dogs were acquired.
- Familiarity to busy urban environments. The researchers noted that Guide Dogs for the Blind Association requires that puppies be exposed to urban environments, and they wanted to examine how that affected future behavior.
- Reported problem behavior. The researchers categorized the dogs into aggression to strangers at home or away from home, aggression to familiar people, aggression to familiar dogs, aggression during veterinary exams, aggression to dogs away from the home, and apprehension/avoidance of a variety of stimuli.
The goal was to investigate how maternal environment (where the puppies were raised prior to ~2-3 months) and exposure to urban environments before 6 months of age affected the dog’s future behavior.
Here are their basic findings:
- Of the 223 dogs that showed avoidance behavior, 68.2% were from non-domestic maternal environments and 39.9% had not been exposed to urban environments between three and six months of age. The researchers write, “Lack of experience of urban environments after three months of age, and non-domestic maternal environments experienced during the first eight weeks of life or longer, therefore appear to be associated with avoidance behaviour.”
- Puppies from non-domestic environments who were rehomed BEFORE the age of 8 weeks were a bit less likely to be aggressive towards unfamiliar people than puppies who left that environment later in life.
- Aggression in veterinary contexts was correlated with being raised in a non-domestic environment, but not with lack of urban exposure as a 3- to 6-month-old.
- Aggression towards familiar people was only weakly correlated with a non-domestic maternal environment. If you excluded the dogs that were aggressive towards unfamiliar AND familiar people, the effect disappeared entirely. In other words, aggression to people appeared to be unrelated to the maternal environment.
- Dogs were slightly more likely to be aggressive towards other dogs if they weren’t exposed to an urban environment as 3- to 6-month-olds, but otherwise, there wasn’t an effect for dog-dog social skills.
The authors conclude that the dog’s early social environment – both with the mother and in puppyhood with the new family – influence development of both avoidance and aggressive behavior as well as social interactions with people and dogs.
There are some important caveats to consider when examining this research:
- Dogs referred to a veterinary clinic for behavior concerns may be more extreme behaviorally (the researchers didn’t give details), so we don’t know how early environments may affect mild aggression or avoidance concerns.
- This is a large sample size, but is limited to dogs that went directly from a breeder to an owner. No shelter dogs were studied.
- There’s a chance that individual dogs (or breeds of dogs) that tend to be raised in non-domestic environments actually have genetic influences that lead to behavior concerns. In other words, the genetics could cause the rearing environment AND the later behavior concerns, rather than the rearing environment causing the behavior concerns.
- This data is over 20 years old as I write this review. Dog populations have changed genetically, dog-owning practices have changed on a human level, and our urban environments are also different. It would be interesting to know how this study plays out in 2021.
- No breakdown on breed, age, neuter status, or potentially traumatic experiences was given in the article. This makes it hard to examine other potential causes or correlates of severe behavior concerns.
So what can you do about it?
There’s one thing that we can really say from this study as well as many others: puppies raised in rich, varied maternal environments AND exposed gently to a variety of stimuli as they age are broadly more likely to adjust well into adulthood.
Socializing young puppies must be done carefully to avoid diseases or traumatic experiences, but this research further supports the idea that happy dogs were exposed to family and urban environments as puppies.
If you got your puppy from a non-domestic environment or live in a rural environment, prioritize getting him or her into socialization classes. Take him or her to Lowe’s or Home Depot or Ace Hardware. Go for short walks on your errand runs into the city.
Give them a chance to familiarize themself with the human world, and do it sooner rather than later.
If you don’t have a puppy yet, prioritize puppies that are raised with domestic maternal environments. Programs like Puppy Culture may help further familiarize your puppy with modern human life.
If you’re a breeder, examine your puppy-raising program to ensure that it meshes with the suggestions and findings from this article.
Kayla is from Ashland, Wisconsin but lives in Missoula Montana. She holds a degree in biology from Colorado College and has spent years working in zoos, animal shelters, as a private dog trainer, and with working detection K9s. She is a Certified Dog Behavior Consultant. She shares her life with her border collie Barley.