My dog, the individual: what influence the breed has on behavior
Until now, there has been a belief that a dog's temperament is largely determined by its breed. A new study has now tested this link -. Comes to an unexpected conclusion.
Courageous, attentive, friendly or relaxed – a new study has now investigated the extent to which a dog's nature is determined by its breed.
Dachshunds are stubborn, golden retrievers good-natured, Great Danes relaxed and German shepherds courageous: When deciding on a dog, future owners consider not only factors such as the amount of exercise and care required, but also the character of the new pet – and with dogs, this is more closely linked to the breed than with any other animal species. Those who acquire a Labrador may do so primarily because they want an uncomplicated family companion – and trust the widely known stereotypical description of this dog breed.
However, a new study published in the journal Science now shows that the link between breed and behavior is nowhere near as strong as previously thought. How closely are genetics. behavior are linked?For her study, Elinor Karlsson, lead author and professor of molecular medicine at UMass Chan Medical School in Worcester, Massachusetts, used the open-source Darwin's Ark database to collect DNA samples from more than 2.000 purebred dogs and crossbreds collected by the research team as part of a genome-wide association study (GWAS).
This is a method of genetic analysis that looks at genetic variations of the genome that occur together with a particular trait of the organism. The main focus is on what are known as haplotypes: specific blocks or rows of gene variants at a specific location on a specific chromosome that are inherited together. Using such genome sequences from people with the same disease, it is possible, for example, to identify the areas in the genome that can be the cause of or a prerequisite for certain diseases.
"Given a large enough sample size, genome-wide association studies are a really powerful tool for finding out more about genetics,", says Kathleen Morrill, a doctoral student at UMass Chan and lead author of the study.
Information about the behavior of dogs of different breeds was obtained by the researchers from the answers in questionnaires, which were also made available to dog owners on Darwin's Ark. More than 18.000 dog owners provided information in this way on behavioral characteristics such as obedience, sociability or their dogs' interest in interaction and toys. In addition, based on the standards published by the American Kennel Club, they gave information about the physical and aesthetic characteristics of the animals.
The scientists next combined genetic analysis and survey data to test the link between genetics and behavioral traits in 78 different dog breeds. In total, eleven sites in the dog genome were identified that are strongly associated with behavioral differences. The team noted: none of these spots were breed-specific. So there are genome sequences that influence behavior – but they occur in individual dogs regardless of breed.
Just like human babies, dogs use nonverbal communication to get what they want.
Breed specific differences only externally
Significant breed-specific genetic differences were only found in genes that control coat color, coat length and other physical traits. Predicting a dog's physical characteristics based on breed was thus five times more likely than predicting behavior in comparison.
The influence of breed on an individual dog's temperament is only nine percent, according to the study. Other factors weigh therefore in relation to certain behavior characteristics substantially more heavily: On the play instinct of a dog for example the age has a clearly larger influence.
The fact that there are behaviors that specifically occur only in one breed of dog could not be proven in the entire study – for every stereotype there are exceptions that disprove it. For example, 90 percent of owners of greyhounds said that their dogs never bury their toys. However, three greyhounds in the cohort did this passionately. Among the Labradors studied – a breed that is not actually prone to howling – eight percent of the animals nevertheless howled from time to time.
The data from the mixed-breed dogs participating in the study were used by the scientists to test the heritability of certain behaviors. It turned out that some behavioral traits, such as obedience, are indeed related to breed affiliation – and their heritability survives the generations. About less hereditary and breed-differentiating characteristics such as frightfulness or excitability, according to the study, only on the basis of the breed but no prediction can be made.
"A dog's personality and behavior are shaped by many genes and life experiences. This makes it difficult to influence these traits through breeding," explains Elinor Karlsson. "Pure breeds of dogs differ in most cases only slightly from other dogs." Thus, the probability of a golden retriever being friendlier is only slightly higher than that of a mongrel or other purebred dog. According to Karlsson, the breed-specific traits that are actually determined by genes are physical criteria: ear shape, size, coat color – but not how friendly or off-putting the dog's nature is.