Stress clearly changes people's behavior. Just think about the last time that you were driving and someone nearly plowed into you. Your driving behavior was probably affected for some time to come.
Short-term stress reactions like this are influenced by hormones. When you experience a stressful event, your body releases the stress hormone cortisol, which is known to affect both the brain and the body.
A paper by mara Mather, Marissa Gorlick, and Nichole Lighthall in the February, 2009 issue of Psychological Science examined how risk-taking behavior was affected by stress both for young adults (between 18 and 33) and older adults (over 65).
To manipulate stress, participants either bathed their arm in warm water for 3 minutes (a low stress condition) or in ice water for 3 minutes (a high stress condition). This manipulation led to higher levels of cortisol release in the high stress group than in the low stress group.
Then, all participants played a risk-taking game in which they had to decide how long to allow a car to keep driving. In this task, participants hold down a button to keep a car driving across a screen. As soon as the car starts moving, the yellow light of a traffic light comes on. This light will stay on between 2 and 7 seconds, and the player gets more points the longer the car stays driving. However, they player has to stop before the light turns red. Otherwise, they lose all of their points.