A surprising new analysis suggests that you may be able to roughly rank the intelligence and trainability of various dog breeds by simply looking at the shape of their heads. Back in the late 1800s through the early part of the 20th century scientists thought that they could estimate the intelligence and the personality of individuals by looking at the shape of their heads and faces. This led to a branch of science called Physiognomy. When we refer to somebody as being "highbrow" or "lowbrow" we are not only making a comment about an individual's cultural tastes and intellect, but we are also using inferences based on measures published in 19th century books on physiognomy. However physiognomy ultimately fell out of favor because of its tendency to draw parallels between the shape of a person's face and head and those of various animals. The idea was that if a person had the features or head shape similar to a particular animal, he must have the personality and intelligence of that animal. This resulted in amusing, but not necessarily believable figures such as the one presented here.
Recently scientists have concluded that there might be a kernel of truth in the belief that measurements of face and head shape can predict certain aspects of personality and behavior. For example, Canadian researchers Justin Carré and Cheryl McCormick of Brock University studied 90 ice hockey players and found that a wider face (where the cheekbone to cheekbone distance was unusually large relative to the distance between the brow and upper lip) was related to the number of penalty minutes a player was given for violent acts (such as slashing, elbowing, checking from behind and fighting). They later concluded that facial dimensions might be related to testosterone levels.
In a study published in the journal Behavioural Processes, psychologist William S. Helton at the University of Canterbury in New Zealand decided to see if the shape of a dog's head was related to its intelligence and trainability. There is certainly a lot of variability in head shape among the various dog breeds. They range from the long-headed dogs, technically called "dolichocephalic", such as Greyhounds or Borzois, to the broader wide-skulled dogs technically called "brachycephalic", which would include the Mastiff and Staffordshire Bull Terrier. In between are the "mesocephalic" (sometimes called " mesaticephalic") such as the Labrador Retriever or Australian Cattle Dog. Actually in classifying a dog, one first has to determine what is called the "Cephalic Index". This is computed by measuring the skull at its widest point and dividing that by the length of the skull and then multiplying the result by 100. You can see how those measures are taken in the accompanying figure.
The rationale for this new study is that the majority of brachycephalic dogs are specialized for fighting and guarding (think Bullmastiff) and the majority of the doclichocephalic dogs are specialized for running (think Greyhound). It is the mesocephalic dogs that are not particularly specialized. According to Helton this lack of specialization might be associated with more cognitive flexibility which in turn could result in dogs that are more easily trained and appear to be more intelligent. While this reasoning appears to be a bit thin to me it nonetheless impelled this psychologist to launch what turned out to be some interesting research.
As a measure of canine intelligence Helton chose to use the ranking of 110 dog breeds that appeared in my book The Intelligence of Dogs. My list was based on a research study in which I contacted all of the dog obedience judges in the U.S. and Canada. Obedience judges are called upon to assess the performance of dogs in various learned activities. At lower levels of competition the dogs are asked to sit, lie down, come when called, and so forth. At higher levels of competition the dogs are asked to respond to signals, go over jumps, retrieve objects, and find items based upon their scent. These judges were asked to rank the breeds of dogs that they had observed in competition using a rather long questionnaire. Fortunately for me more than half of the judges in North America at that time completed this ranking. The results were remarkably consistent, and subsequent studies have confirmed that there are predictable differences in the intelligence of various breeds (as measured by their trainability). For more information on this ranking of dog breeds you can see my previous article on this subject by clicking here.
In this current analysis the rankings of the various dog breeds for their working and obedience intelligence was compared to their cephalic index. The results were consistent with what Helton had originally predicted. He found that as a group the dogs with the intermediate head shape (mesocephalic dogs) ranked considerably higher in intelligence than either the dogs with the long narrow heads (the dolichocephalic dogs) or the dogs with the shorter broader heads (brachycephalic). There were exceptions, such as the fact that the Poodle, a dolichocephalic dog, ranks number two, while the basenji, a mesocephalic dog ranks second from the bottom in trainability. However if we look at the grouped results, we find that 16 out of the top 22 dog breeds that were ranked highest in intelligence were mesocephalic, while only 5 out of the 22 breeds ranked lowest in intelligence were mesocephalic.
One must be careful in interpreting such results, since the cephalic index is a continuous measure that gradually moves from brachycephalic to dolichocephalic. Because of that one must establish arbitrary values to define the groups which means that the results might be affected by where we put our cutoff points marking the various categories of head shape. Furthermore, the measures of what I call intelligence have been interpreted by some other researchers to reflect "trainability" rather than a general intelligence factor. Regardless of those considerations, the interesting finding brought to us by this research is that by simply glancing at the head shapes of the various individuals in a group of dogs we can make a rough guess at which ones are going to be the easiest to train and which will learn the best.
Stanley Coren is the author of many books including: The Wisdom of Dogs; Do Dogs Dream? Born to Bark; The Modern Dog; Why Do Dogs Have Wet Noses? The Pawprints of History; How Dogs Think; How To Speak Dog; Why We Love the Dogs We Do; What Do Dogs Know? The Intelligence of Dogs; Why Does My Dog Act That Way? Understanding Dogs for Dummies; Sleep Thieves; The Left-hander Syndrome
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