MONDAY, June 11, 2012 (HealthDay News) -- People with lower levels of the brain chemical dopamine are more likely to be highly aggressive in competitive situations, a small new study indicates.
Dopamine is a neurotransmitter that is involved in pleasure and reward.
The study included 18 healthy participants in their 20s who played a computer game in which they could win money. They were told, however, that an opponent in another room who was able to cheat may steal some of their winnings.
PET scans were used to assess dopamine levels in the participants' brains.
During the game, participants with lower levels of dopamine were more distracted from their attempts to win money and were more likely to show aggressive behavior, wrote study author Dr. Ingo Vernaleken, of the department of psychiatry at RWTH Aachen University in Germany, and colleagues.
The researchers were surprised by the results because they expected to find that higher levels of dopamine were associated with increased aggression.
The study was scheduled for presentation this week at the Society of Nuclear Medicine's annual meeting in Miami Beach, Fla.
Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed medical journal.
The American Psychological Association offers strategies for anger control.