Does a Dog's Head Shape Predict How Smart It Is?
Two studies find that head shape may be related to canine intelligence.
Posted March 1, 2023 | Reviewed by Gary Drevitch
- Two studies relate canine head shape to intelligence and problem-solving.
- The larger study contained data from 196 dog experts who assessed the intelligence 133 dog breeds and associated it to canine head shape.
- Both studies agreed that short-faced dogs solve problems less efficiently and rank lower in intelligence than medium or long-faced dogs.
Most of us know that the term "highbrow" refers to an intelligent person who is interested in learning, culture and art. That term is actually a holdover from phrenology, an early discipline of psychology which believed that aspects of a person's personality and mental abilities could be read from the shape of their skull. Thus, in the 1870s, phrenology proclaimed that people with large foreheads were more intelligent, contrasted to "lowbrows" with smaller foreheads who were deemed to be less intelligent and cultured. Phrenology has been mostly abandoned by psychologists interested in human behavior; however in recent years, it has been making a bit of a resurgence in terms of predicting the behavior of dogs.
Our selective breeding of dogs has modified their size and shape dramatically. That is why the more than 400 accepted breeds of dogs are easily recognizable based on their physical characteristics. It also appears that there is some correlation between a dog's head shape and the functions that they perform for humans; for example the sighthounds (who pursue game over open ground) tend to have long narrow heads, while many of the guarding breeds tend to have more square-shaped heads. A new study, headed by Dorottya Ujfalussy in the Department of Ethology, at Eötvös Loránd University in Budapest, Hungary, offers the suggestion that a dog's head shape may predict its intelligence and problem-solving ability as well.
The Shape of a Dog's Head
The head shapes of canines range from the long-headed dogs, technically called "dolichocephalic" (such as the Afghan Hound or the Greyhound), to short-faced dogs with broader wide-skulled dogs technically called "brachycephalic" (such as the Pug or French Bulldog). In between are the "mesocephalic," which includes the Golden Retriever or the Beagle. You can see some examples below.
The usual way to determine a dog's head shape involves computing what is called the "Cephalic Index." To do so, you measure the skull at its widest point (in millimeters), then divide the result by the maximum length of the skull and finally multiply the result by 100. You can see how such measures are taken in the figure below. Smaller values are associated with dolichocephalic dogs (long-headed) and larger values indicate brachycephalic dogs (short-headed). The mesocephalic dogs fall in between (index values between 50 and 60).
A Recent Small Study
This new research was a relatively limited experiment involving only two brachycephalic breeds of dogs (15 English bulldogs and 15 French Bulldogs) and one mesocephalic breed of dog (13 Hungarian Mudis — a Spitz-derived medium-size herding dog). The test for intelligence involved requiring the dogs to solve three different puzzle problems.
The data showed that the two brachycephalic breeds were less successful at solving problems and took longer even when they did manage to solve them. While this data is suggestive, the use of only two brachycephalic breeds and one mesocephalic breed greatly limits our ability to generalize these results. This is because there is so much variability in canine intelligence, even among dogs with similar head shapes. For example, the Border Collie is ranked very highly in working and obedience intelligence while the Beagle scores much lower, even though both are mesocephalic breeds.
Analysis of a Larger Data Set
When I encountered this report it occurred to me that the question was interesting. The fact that so few breeds were tested, however, was unfortunate. Then I remembered that I still have a databank on the personality traits of 133 individual dog breeds which I collected for one of my books (Why Does My Dog Act That Way). The data were based on ratings by 96 dog experts, who each contributed a long number of hours to rank dog breeds on five different behavioral dimensions. One of these dimensions was Intelligence/Learning ability which is a measure of how easily a dog learns and solves problems. The results were then pooled and the breeds ranked. Ultimately each dog breed was assigned a score based on its ranking ranging from 1 (the lowest 25 percent) up to 4 (the highest 25 percent)
I had never before analyzed these data in terms of the head shape of dogs so I went back and re-coded the information for each breed to include head shape, using the same scoring method employed by O'Neill's research team in 2020.
The statistical analysis of the results is quite easy to describe. The overall result shows that head shape does matter, in a small but statistically significant way. There is virtually no difference in terms of intelligence ranking between the mesocephalic and the dolichocephalic breeds of dogs. However, the brachycephalic breeds of dogs ranked significantly lower than dogs with either of the other head shapes. The differences may not be large enough to breathe life again into the nearly forgotten discipline of phrenology, but they are interesting.
Some Unresolved Questions
The reasons why the brachycephalic breeds of dogs tend to score lower are not clear. It could have to do with genetic and physiological differences. Such changes might have arisen during the course of domestication and the genetic selection for a short-faced skull shape.
However, the differences might also be due more to personality than to intelligence. The Hungarian researchers point out that the two brachycephalic breeds that they tested spent more time looking at their owner than did the mesocephalic dog breed. It is possible that the dogs may be looking at their owners seeking help to solve the problem, or perhaps simply looking for social reassurance and affection. Still, for whatever reason, when a dog is distracted because it is attending to a nearby human it is not fully focused on the problems that have been set before it. This will make solving those problems slower and less efficient and make the dog appear to be less intelligent on such tests.
Copyright SC Psychological Enterprises Ltd. May not be reprinted or reposted without permission
Statistical Note: The statistical analysis of the larger databank involved a one-way analysis of variance, using the intelligence rankings grouped by the three head shape categories and the result was F = 3.34, df=2, p<0.05.
Ujfalussy D, Bognár Z, Molnár M, Miklósi A, Kubiniy E (2023). The difference between two brachycephalic and one mesocephalic dog breeds' problem-solving performance suggests evidence for paedomorphism in behaviour, Research Square [https://doi.org/10.21203/rs.3.rs-2567976/v1]
Coren, S. (2006). Why does my dog act that way? A complete guide to your dog’s personality. New York: Free Press
O’Neill DG, Pegram C, Crocker P, Brodbelt DC, Church DB, Packer RM. (2020). Unravelling the health status of brachycephalic dogs in the UK using multivariable analysis. Scientific Reports. 14;10(1):1-3.