I have been ploughing through a very learned (for me) article by Holly Stone, Melissa Starling, Paul McGreevy and Bjorn Forkman published a few weeks ago, on correlations between changes in morphology (the branch of biology concerned with the form and structure of organisms) and behaviour.
I have tried to pluck out the essence of the results of the studies without possible explanations – please go to the article for the information. Skimming to the end to the conclusion where it was summarised, I have tried to put into some order the main points.
What caught my interest was ‘as height and weight decrease, many undesirable behaviours (non-social fear, hyperactivity and attention seeking) become more apparent’.
Shorter dogs demonstrate more generalised aggression than taller dogs, while taller dogs show more affection, cooperation and playfulness (with humans).
There is always a danger in generalising but the exceptions make the rules as they say. I myself can actually think of as many exceptions in dogs I have been to as I can of dogs that conform to these definitions.
I have tried to summarise the summary – the breeds in italics are my own additions to make it a bit more readable:
- Heavier, shorter and brachycephalic dogs (English Bulldog?) demonstrated more aggression toward the ghosts (assistants dressed in white capes),
- Heavier, shorter dogs were also more likely to be aggressive in response to the sudden appearance of the dummy (a boiler suit). Aggression therefore inversely correlated with both bodyweight and height.
- Lighter dogs demonstrated more aggression toward the assistant. Stranger-directed aggression in short dogs correlated inversely with bodyweight.
- In shorter dogs (Daschund?) owner-directed aggression was more prevalent.
- Male dogs were more likely to be aggressive toward the dummy, while female dogs were more aggressive toward the assistant. (The dummy is designed to startle dogs with its sudden appearance, whereas the assistant walks toward the dog in a crouching manner over a longer period and eventually invites play with the dog).
Chase proneness, holding and possessiveness:
- Brachycephalic dogs and heavier dogs showed greater interest in chasing and holding prey-like objects. Bodyweight was positively correlated with chase proneness.
- Brachycephalic dogs showed more chase proneness than dolichocephalic dogs (like Afghan Hounds actually bred to chase prey, which is surprising).
- As bodyweight increased, possessive behaviours became more prevalent. These heavier dogs were more inclined to grab and hold a toy than those with a lower bodyweight. Heavier male dogs were especially likely to engage in tug-of-war.
- Males in general demonstrate more interest in possession games.
Boldness and inquisitiveness:
- Heavier dogs (Rottweller?) tend to be bolder, more inquisitive and attentive, whereas lighter dogs (Whippet?) tend to be more cautious and fearful.
- Heavier dogs that showed more interest in exploring the dummy or the source of a metallic noise.
- Heavy dogs were the most inquisitive toward the assistant, and heavy males demonstrated prolonged inquisitiveness toward the dummy.
Affectionate and sociable:
- Taller, brachycephalic dogs were more affectionate, cooperative and interactive with unfamiliar humans.
- Lightweight, tall and brachycephalic dogs were the most affectionate.
- In terms of sex, low-bodyweight females were especially affectionate when handled. That said, male brachycephalic dogs were also reported as being affectionate.
- Brachycephalic, tall, male dogs were both more playful and sociable with humans.
- Lighter dogs were especially likely to be excitable, energetic and hyperactive (Cocker Spaniel?).
- Lighter, dolichocephalic dogs were the most cautious of metallic noise and showed prolonged fearfulness.
- Lighter, dolichocephalic female dogs were the most cautious and startled by a suddenly appearing dummy.
- Brachycephalic, tall females with a low bodyweight were the most fearful of the gunshot.
- Attachment and fear were associated with shortness
- Dolichocephalic females, short females and heavy male dogs demonstrated fearfulness of the ghosts (dolichocephalic and short dogs have a greater tendency to show fear though heavy males to be fearful of the ghosts).
- Lighter dogs were also found to be the most cautious and fearful.
Maybe we select our dogs using the wrong criteria.
An interesting one to me is ‘Brachycephalic, tall females with a low bodyweight were the most fearful of the gunshot’ as I was hoping a link could be helpful. But on looking through the stories of the more recent dogs I have been to that are afraid of gunshots and bangs, I could see nothing that backed up this pattern. So there you go!
Here is the story of one dolichocephalic, tall(ish) lightweight(ish) female terrifed of bangs, and the story of a brachycephalic dog, a Staffordshire Bull Terrier, who was terrified of bangs – a male.