Adrenaline is a substance released in the body when a person feels a strong emotion, such as excitement, fear, or anger. The adrenaline rush usually occurs when the body senses danger, the “fight or flight” moment.
Some people, known as sensation-seekers, are adrenaline junkies. Psychologist Marvin Zuckerman defines sensation-seeking behavior as the pursuit of novel and intense experiences without regard for physical, social, legal, or financial risk. Sensation-seeking is a general personality trait. And like any personality trait, it is more than 50 percent determined by heredity.
Extreme sports can be a natural fit for adrenaline junkies. These activities include bungee jumping, rock climbing, and auto racing — any activity that involves a significant level of danger. Some people find thrill through non-sports activities or jobs, such as firefighting, police work, or the military. Sensation-seekers may find the riskiness of these careers part of the attraction.
The movie The Hurt Locker demonstrates the lure of an adrenaline rush. The movie begins with this quotation from war correspondent Chris Hedges: "We imagine war is tough. We know it puts great strain on soldiers. But is war a drug?" The movie focuses on the guys whose daily job is to disarm the homemade bombs that have accounted for most U.S. casualties in Iraq. One character, in particular, the supremely resourceful staff sergeant played by Jeremy Renner, is addicted to the almost nonstop adrenaline rush and the opportunity to express his esoteric skill.
In the case of “runner’s high,” running produces a flood of endorphins (a kind of internal morphine, which suppress pain) in the brain. For example, people who are injured in the heat of sports competition, or in battle, often don’t notice their injury until the action stops. These endorphins are associated with mood changes. It’s not unusual for an avid runner to start running regularly for a few miles and then slowly increase to 10 to 15 miles to feel the satisfaction of a workout. They develop a sort of tolerance to high-intensity activities.
People who seek high-sensation experiences are more vulnerable to substance abuse. Sensation-seekers tend to perceive more benefits and fewer risks in drinking, for example, than do low sensation-seekers. Scientists have discovered some similarities between the brains of drug users and high sensation-seeking athletes. The connection comes down to dopamine, a chemical associated with the brain’s pleasure reward system. High sensation-seekers may be overstimulated by novel experiences, because their brains release more dopamine during these events than those of low sensation-seekers. This feeling of pleasure and satisfaction leads the sensation-seeker to come back for more. Because the sensory cues and actions that precede and occur with those pleasurable experiences are remembered.
The sensation-seeking trait may have been useful to early humans. Without risky experiences, there would be little impetus for discovery. Neurologist Elkhonon Goldberg (2009) writes that the great globe-trotting Christopher Columbus would have never embarked on his great voyage had he not been temperamentally dysphoric and had Prozac been available in those days. The need for novelty has made us who we are — intelligent, curious, and constantly seeking the next good thing. Novelty-seeking behavior is a basic need, not a compulsive behavior. There is a thin line between normal and pathological behavior.