So is genetic testing and careful selection enough

Yes, this is what I find interesting. There is a large genetic component associated with mental health issues, particularly schizophrenia and bipolar disorder in humans. We know this from epidemiological studies. Does this translate into our canine population?
There are 1,300 guide dog puppies born each year, and I imagine the figures haven't changed that much over the last 5 years? so that's 6,500 puppies with a success rate of 5/6, so 5,000 puppies have made it through over the the last 5 years. That's phenomenal. I suspect that the heritability factor scores quite highly here, higher than suggested in the last link, I think of around 20-30%? although granted the puppy walkers play a huge part in this figure.

 

The test I posted a link to is for adult dogs. But, I took the Volhard puppy test with me to visit the breeder when Oban was a puppy. It was fun and interesting but all four males scored very close together and I could see greater differences myself just by observing them. Plus, it's meant for puppies but I thought some parts were better geared to older than 8 weeks. I gave up on it but it was fun.

 

There have been a couple of mentions of mental health disorders in humans. Just want to point out that mental health disorders (schizophrenia, bipolar disorder, major depression) are not ‘personality’ and are instead best likened to other physical illnesses. If a mental health disorder has a heritable component this tells us nothing about the hertability of personality factors - in humans or dogs.

 

I think the first indicator of how important Nature (genetics) is the general characteristics of the different breeds. We have had one Malamute, and three Labs. All of them were pretty true to the typical breed expectations. The Malamute was more independent, harder to train and had much more prey drive. Our three Labs have all had Lab personalities. While they were all different, all were fairly easy to train, not easily upset, loved to play, retrieve, swim, not inclined to fight and seemed very unlikely to ever bite a person.

Our first Lab, Ginger, was a rescue, but apparently came from a good home, where she was well treated and well trained. With our other two, Tilly and Cooper, we did as much research as we could on parents, though not as much as some folks on this forum.

I understand that Guide Dogs for the Blind in Oregon has a very high success rate, in part because of a careful breeding program to get the traits they want in a guide dog. I believe that most of their dogs are Yellow Labs.

 

I think in dogs we would label them as personality traits, for want of better diagnosis? As I said, they are a physiological issue but they certainly affect the way a person (or dog) behaves.
But, this begs the question: is a nervous disposition in either a canine or a person physiological/neurological? I think it often likely is.

 

If you look at shyness in humans it's interesting.

 

My son was the shyest boy I’ve ever met, and after teaching for 40 years I’ve met a lot!

Now he’s outgoing, sociable and a nurse in Germany having trained entirely in German.

Which shows, imo, that shyness can be overcome

His Dad, on the other hand ....

.

 

Personality is pretty malleable. In both humans and dogs.