EMOTION DOESN'T CAUSE BEHAVIOR. IT IS A BEHAVIOR.
Treated as such, it can be examined, measured, and it can be changed.
A behavior is caused by some change in the environment. There are two kinds of behaviors - respondent and operant. Here is the down and dirty difference. Respondents are involuntary and are difficult to observe because they predominantly happen inside the dog. Chemical releases and reflexes fall into this category. They do have some external, observable manifestations like increased respirations, dilated pupils, increased blood flow observable in some dogs with eyes and ears “pinking up.”
Fun fact: These internal, hard-to-see behaviors account for some of the "it happened out of nowhere" scenarios. It is important to remember that lack of overt, observable behavior does not equal your dog being "fine."
Operant behaviors are voluntary and the dog can exhibit these behaviors - or not - depending on lots of factors that we won’t dive too deeply into here. You can think about this in terms of behaviors that can be strengthened with reinforcement or weakened with punishment. Note: Because they are involuntary, respondent behaviors do not respond to consequences - this is why comforting your dog during a scary experience does not reinforce fear or anxiety.
Ok, I used two big labels - fear and