Do dogs have stable personality traits?

We often talk about people having particular personality types, such as extroversion/introversion. Is it true that dogs have particular personalities too, and are they fixed or do they change over time? A new study by Jamie Fratkin (University of Texas at Austin) and colleagues takes a look at this.The question is useful to many people. Trainers of guide dogs, police dogs and other service dogs would really like to be able to spot suitable candidates at a young age, so as not to waste time […]