Just as there are automatic and difficult to control physical body processes that contribute to stress, so too are there automatic and difficult to control mental processes that contribute to stress. Biofeedback techniques can be used to help people gain conscious control over their bodily stress processes, and cognitive techniques can be used to help people gain conscious control over their mental stress-inducing processes.
The degree to which stressed people will become in a given situation is in large part determined by the appraisals they make concerning how threatening that situation appears to be, and how prepared they are to handle the situation. It is the perception of danger, rather than the objective reality of danger, that counts in determining how stressed and anxious a person is likely to become.
Broadly, two factors influence the appraisal process: emotion, and logic or rational thought. Emotion is almost always the stronger of the two influences, but it is generally not the most accurate. For instance, children interpret events primarily by using their emotions. They make predictions about the world that are sometimes wildly wrong, but they don't always notice that error has occurred, because those predictions feel true and that feeling of truth is good enough for them. Children can't help but to appraise things in this emotional manner; they are limited by their level of brain development. It is not until they approach the teen years that children's brains become physically mature enough for them to make decisions in a more systematic, logical and evidence-based manner.
Despite maturing physically, many people never fully grow out of their emotional reasoning habits, and persist in making decisions and appraisals that are primarily driven by their emotions well into adulthood. This tendency is problematic because emotionally driven appraisals, made on the basis of how people feel and not on the basis of what is real, often lead to exaggerated or inadequate responding. The cognitive models developed by Drs. Ellis and Beck teach us that our appraisals influence our moods, and when our appraisals are distorted and exaggerated, so too will be our moods. People can therefore learn to better control their stress if they can gain more awareness of and better control over their appraisal process.
From the cognitive perspective, the question of whether or not people's appraisals will cause stress comes down to the presence or absence of cognitive distortions and dysfunctional beliefs in their minds which, when present, will tend to interfere with judgment and alter mood for the worse.