But beyond breed-related predispositions, what other behaviors can be inherited? Patricia identified five, although she freely admitted that two of them are based on personal speculation alone. The other three have some science that show they tend to be pretty stable over time.
The first, and possibly the most researched, is shyness. Shyness is not the same as docility. It has nothing to do with submission. And it doesn’t really tell you how the dog will act. Shyness, scientifically speaking, has to do with fear of the unfamiliar.
This behavioral trait is actually a continuum, with shyness at one end and boldness at the other. It is influenced by the level of cortisol, the HPA axis, and the activity of the amygdala. A study by Goldsmith and Lemery demonstrated that it is surprisingly stable through an individual’s life. They discovered a correlation between a child’s cortisol baseline and his mother’s, and found that the baseline level taken one and a half years before a child started school could predict a teacher’s evaluation of inhibition at age seven.
In other words, shyness is strongly linked to genes, and is incredibly easy to pass on. This makes sense from an evolutionary standpoint: the child (or monkey or rat or cat- all have been studied) who runs from something new and unfamiliar stands a better chance of surviving than the one who boldly investigates strange and potentially dangerous things. It also makes sense then that shyness is expressed early in an individual’s development. Patricia shared that Margaret Seary Young found it was the only trait reliably predicted on puppy tests.
Reactivity is “mediated by physiology,” Patricia told us, and it is therefore logical that it would be influenced by genetics. Reactivity here does not refer to the bark-growl-lunge type of behavior problem that we dog people usually define it as. In this case, it simply has to do with how quickly and how much a dog responds to its environment.
Reactivity can be desirable in certain contexts- a herding dog that doesn’t have a short reaction time probably won’t be very good at his job. On the other hand, there are times where you need a “bomb-proof” dog who doesn’t really notice, much less respond to, what’s going on around him.
It’s also important to know that reactivity is separate from the shy/bold continuum. A very bold dog might notice and respond quickly to his environment, although he will probably do it in very different ways than the shy dog does.
Another behavioral trait that seems to have a genetic influence is frustration tolerance because it is mediated, in part, by the amygdala. However, there also appears to be a strong environmental component to frustration tolerance as well. Who can’t relate to being more irritable when tired, hungry, or in pain?
A dog who is having difficulty tolerating frustration is more likely to act out aggressively. Interestingly, aggressive dogs typically show lower amounts of serotonin and higher concentrations of cortisol, which also suggests there's a link to genes.
The last two behaviors are the ones that don’t (yet) have any scientific research to back up: predisposition to use mouth and status seeking. Both of these traits are things that Patricia has observed enough to believe they are genetically inherited. For the first, she says it just makes sense. Australian Cattle Dogs, for example, would need to use their mouths in order to herd cows. As for status seeking, Patricia said there seem to be puppies that are interested in controlling resources at a very early age… but more on that soon.
It’s clear that there are a number of behavioral traits that have at least some genetic influence. They go beyond just breed-related tendencies, and help explain why two dogs of the same breed can act quite different from one another. Of course, we already know that the environment is an important factor, too. In my next entry on the seminar, I’ll tell you about some of those factors, including in utero experiences, early stimulation, and socialization.
If You Want to Know More
- Linking temperamental fearfulness and anxiety symptoms: a behavior-genetic perspective, an article by Goldsmith and Lemery
- The genetic contribution to canine personality, by Saetre et al This study found that shyness/boldness has a strong genetic component.
- Shyness-boldness predicts performance in working dogs, by Svartberg
- Blood concentrations of serotonin, cortisol and dehydroepiandrosterone in aggressive dogs, a study by Rosado et al
- Breed Differences in Canine Aggression, a surprising article by Duffy, Hsu, and Serpell
- Behavior Problems in Dogs, by William Campbell, the book which introduced the concepts of “passive defense reflex” and “active defense reflex.”