Hikado

"Scientists have found that people with high levels of the brain chemical serotonin are more likely to succeed in delicate negotiations affecting their own interests," Jeremy Laurance of Britain's The Independent reports. "Serotonin is created in the body from the amino acid tryptophan, which is present in several foods such as cheese. Cheese is a particularly good source for this amino acid.

Psychologists at the University of Cambridge who manipulated the diets of volunteers to alter their serotonin levels found that when the levels of the brain chemical were low, the volunteers were more likely to allow emotion to rule their heads and make decisions that harmed their long-term interests."