Dogs' "Teenage Brains" Evolved for Good Reasons

Dogs, like so many other nonhumans, go through a period called "wildhood."

Posted May 13, 2020

"Moody, unpredictable and with an striking disregard for the rules, teenagers can be hard to handle. Now it turns out the same is true for adolescent dogs." —Nicola Davis

"Like teenagers—whose bodies flood with hormones and whose brains are rewired during puberty—adolescent dogs can disregard and disobey their owners." —Virginia Morell

"All animals need time, experiences, practice, and failure to become mature adults.” —"Astounding Connections Between Human and Animal Adolescents"

I recently learned of an extremely interesting essay published in Biology Letters by Newcastle University's Dr. Lucy Asher and her colleagues called "Teenage dogs? Evidence for adolescent-phase conflict behaviour and an association between attachment to humans and pubertal timing in the domestic dog."1 This paper is available online, so here are a few snippets to whet your appetite for more.

Two excellent summaries can be found in Nicola Davis' "Dogs endure emotional difficulties in puberty like humans, says study" and Virginia Morell's "Dogs get difficult when they reach adolescence, just like human teenagers." All of these pieces reminded me of a fascinating interview I conducted with Barbara Natterson-Horowitz and Kathryn Bowers, the authors of Wildhood: The Epic Journey from Adolescence to Adulthood in Humans and Other Animals. In their interview and in Wildhood, the authors stress how difficult adolescence can be in a wide range of nonhuman animals (animals), and how necessary it truly is. In this essay in addition to discussing research on dogs' teenage brains, I take a different, evolutionary approach, to why teenage brains have survived for eons in diverse animals.  

Let's first return to the research at hand. Dogs begin puberty at around six-to-nine months of age. To study dogs' teenage years, Asher and her colleagues worked with 70 potential female guide dogs, including German shepherds, golden retrievers, Labrador retrievers, and mixes of these breeds. During adolescence, hormonal and brain changes strongly influence different types of behavior including Attachment and Attention Seeking. Using the C-BARQ (University of Pennsylvania canine behavioral assessment and research questionnaire)2, the researchers gathered information on behavioral changes that were measures of insecurity. They write, "The first, Attachment and Attention Seeking, was scored as a mean of six behaviours related to proximity seeking (e.g. 'Tends to sit close to or in contact with you…’, ‘Displays a strong attachment for one… member of the household’) and the second, Separation-Related Behaviour, was scored as a mean of nine behaviours (e.g. ‘Shakes shivers of trembles when left, or about to be left’, ‘Appears agitated…when separated from you…’)." 

To rule out that behavior changes weren't due simply to general fearfulness, the researchers then studied anxiety. They learned that general anxiety was not associated with puberty. They also learned that there were declines in obedience and trainability. "Carers [people with whom the dogs were living] ... assigned lower scores of Trainability to dogs around adolescence (8 months), than pre-adolescence (5 months of age) and post-adolescence (12 months)...By contrast, the dog's trainers reported an increase in Trainability when adolescent." 

Here's a summary of this fascinating and novel study:

  • There was "...an association between earlier puberty and an insecure attachment to a human carer." 
  • They learned that "...when dogs reached puberty, they were less likely to follow commands given by their carer, but not by others."
  • They also learned that "...the reduction in obedience to the carer and not an ‘other’ person to be specific to the dog's developmental stage and more pronounced in dogs with insecure attachments, which is not easily explained by differences in dog training ability between the carer and other."
  • They also reported that "...conflict behaviour is associated with less secure carer attachments during an adolescent-phase, because behaviour indicative of insecure or anxious attachments was only associated with obedience at an age that corresponds with adolescence."

I'm very pleased to see this study and its results are in agreement with what the authors of Wildhood also learned, namely, "New studies are showing that negative adolescent adversity in rodents, dogs, numerous wild species and humans is correlated with behavioral disturbances and reduced survival later in life."

Domestication didn't alter dogs' problematic puberty and recalcitrant behavior 

One final note that's important from an evolutionary perspective is that dogs' teenage brains and difficult and challenging adolescence weren't lost during domestication, when human/artificial selection replaced natural selection. In this interview, we read, "All animals need time, experiences, practice, and failure to become mature adults.” So, humans' presence really didn't do anything to dogs who had a lot of human care, and clearly there's some survival value in making it through puberty despite how difficult it might be for the dogs and their humans.

In biological parlance, there has been stabilizing selection for wildhood because it is an important and necessary sensitive period for numerous nonhumans. Stabilizing selection is "a type of natural selection in which genetic diversity decreases and the population mean stabilizes on a particular trait value." Via stabilizing selection, traits can be retained that are advantageous, while outliers are selected against and disappear. Dogs' pubescent teenage brains evolved for good reasons.

I look forward to further studies on the teenage brains of dogs and other animals, including individuals of other domesticated species. Dogs came from wolves, and they have retained a variety of traits that their wild relatives display. It would be very useful to gather comparative data on the children of free-ranging or feral dogs who have had little to no contact with humans to see how they experience adolescence. Based on the study discussed above, there's no reason to assume that they wouldn't also experience wildhood, and when and if humans disappear, we can feel comforted that post-human dogs will still have brains that enable them to learn various skills that would be needed for them to make it on their own. But that's another fascinating and exciting story.3

References

Notes

1) Their abstract reads: "The relationship between parent and child changes around adolescence, with children believed to have: (i) an earlier puberty if they have less secure attachments to their carer; (ii) a phase of increased conflict behaviour toward their carer; and (iii) heightened conflict behaviour when carer attachments are less secure. We find support for analogous associations in adolescent dogs based on behaviour and reproductive timing of potential guide dogs. Bitches with behaviour indicative of insecure attachments pre-adolescence became reproductively capable earlier. Providing the first empirical evidence to our knowledge in support of adolescent-phase behaviour in dogs, we found a passing phase of carer-specific conflict-like behaviour during adolescence (reduced trainability and responsiveness to commands), an effect that was more pronounced in dogs with behaviour indicative of less secure attachments. These results indicate a possibility for cross-species influence on reproductive development and highlight adolescence as a vulnerable time for dog–owner relationships."

2) Hsu, Y. and Serpell, J. A. Development and validation of a questionnaire for measuring behavior and temperament traits in pet dogsJ. Am. Vet. Med. Assoc. 223, 1293-1300, 2003.

3) Jessica Pierce and I have just completed a book called Dogs Gone Wild: Imagining the Lives of Dogs in a World Without Humans we began long before the current COVID19 pandemicFor further discussion and speculation about the fate of post-human dogs, see: How Will Dogs Reshape Nature Without Humans to Control Them?As Dogs Go Wild in a World Without Us, How Might They Cope?Puppy Mills, Pandemics, Disaster Preparedness, and Decency, and "I'm a Mess About My Dogs and Coronavirus—How Will They Do?"