Serotonin may affect our sense of fairness, scientists report

The neurotransmitter serotonin, which acts as a chemical messenger between nerve cells, plays a critical role in regulating emotions such as aggression during social decision-making, new research by scientists at England's University of Cambridge and UCLA suggests. Their findings appear June 6 in the peer-reviewed journal Science.
 
Serotonin has long been associated with social behavior, and low levels of serotonin are associated with depression and anxiety, but its precise involvement in impulsive aggression has been controversial. Though many scientists have hypothesized a link between serotonin and impulsivity, this is one of the first studies to show a causal link between the two.
 
The findings highlight why some of us may become combative or aggressive when we have not eaten. The essential amino acid necessary for the body to create serotonin can only be obtained through diet; our serotonin levels naturally decline when we don't eat.