Short Synopsis: The researchers looked at the histories of dogs who came to a vet for problems with fear or aggression. The researchers excluded any dogs whose histories before the age of 6 months were unknown, because the goal was to see how early life experiences and behavioral problems were related.
The dogs were divided along 3 main criteria:
- Those raised in domestic (inside the home) environment as young puppies versus those raised in non-domestic environments (kennels, sheds, shelters, outdoors)
- Divided by the age they were acquired by the
owners ividedby whether or not they’d been exposed to a busy urban environment between the ages of 3 and 6 months.
The researchers found that:
- Puppies raised in non-domestic environments were more likely to show avoidance behaviors and aggression towards unfamiliar people.
- Puppies not exposed to urban environments between the ages of 3 and 6 months were more likely to show avoidance behaviors and aggression towards unfamiliar people.
- 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 puppyhood environment. If you excluded the dogs that were aggressive towards unfamiliar AND familiar people, the effect disappeared entirely.
- 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.
In conclusion, to quote from the abstract:
“These results support the suggestion that there is an association between a dog’s early environment and the development of fear-related behavioural problems (Serpell and Jagoe 1995). The provision of a rich social, and stimulating physical, environment, by both breeders and owners, during the first six months of a dog’s life, appears to be associated with a reduced incidence of some kinds of problem
behaviour, and may thereforebe of general benefit to canine welfare.”
Authors: D. L. Appleby, J. W. S. Bradshaw, and R. A. Casey
Publication: Veterinary Record
Publication Date: April 2002
Applies To: early life experiences, aggression
Sample Size: 820 dogs
Limitations/Drawbacks: only looked at dogs who had severe enough behvavioral issues to see a vet for the problem.