Movies sometimes feature a scene where a character gets in a car, slams the door and then speeds off in a huff of anger, and you just know the subsequent scene will inevitably show a terrible car accident, followed by a shot of the victim's loved ones grieving.
A car suddenly cuts you off while you are happily driving along on the highway, causing you to come to a sudden halt, your chest painfully colliding with the steering wheel. What do you do? (a) take a deep breath and continue on your way; (b) honk the horn and continue; or (c) repeatedly honk your horn, swearing and punching the steering wheel, all the while mumbling angrily, wondering how the driver could ever have gotten his license.
Research shows that drivers operating their cars while angry or overly excited are twice as likely to get into an accident compared to emotionally neutral drivers. These emotional states affect the sympathetic nervous system, releasing 2 types of hormones: epinephrine (adrenaline) and norepinephrine (noradrenaline). The sudden increase in these two substances will increase blood pressure and distress the excitatory and inhibitory nerve pathways, causing the driver to take more risks, take over lanes, speed, overtake recklessly, or suddenly change lanes. This results in serious accidents for both themselves and for others.