As with much of what I post here, I try to incorporate the "science" with the "practical" work being done by negotiators. The following ten articles are all grounded in research and can be helpful from a understanding the physiology of stress, how to manage stress, and how it impacts decision-making.
How Anxiety Affects Your Decision-Making Skills
New research points to the connection between bad choices and anxious personalities.
Decision-Making Under Stress: The Brain Remembers Rewards, Forgets Punishments
It's counterintuitive, but under stress we tend to focus more on the rewards than on the risks of any decision.
A new review shows that acute stress affects the way the brain considers the pros and cons, causing it to focus on pleasure and ignore the possible negative consequences of a decision.
Understanding the stress response
Chronic activation of this survival mechanism impairs health.
All of these changes happen so quickly that people aren't aware of them. In fact, the wiring is so efficient that the amygdala and hypothalamus start this cascade even before the brain's visual centers have had a chance to fully process what is happening.
Just made a bad decision? Perhaps anxiety is to blame
Scientists have discovered a mechanism for how anxiety may disrupt decision making. They report that anxiety disengages a region of the brain called the prefrontal cortex, which is critical for flexible decision making.
Once the fear pathways are ramped up, the brain short-circuits more rational processing paths and reacts immediately to signals from the amygdala. When in this overactive state, the brain perceives events as negative and remembers them that way.
...Moreover, fear can interrupt processes in our brains that allow us to regulate emotions, read non-verbal cues and other information presented to us, reflect before acting, and act ethically. This impacts our thinking and decision-making in negative ways, leaving us susceptible to intense emotions and impulsive reactions. All of these effects can leave us unable to act appropriately.
How You Deal With Your Emotions Can Influence Your Anxiety
Stress And The Brain: High Cortisol Levels Can Damage Brain Structure, Cognitive Function