Study: Fairness wired in the human brain

LOS ANGELES, May 29 (UPI) -- California Institute of Technology researchers say the concept of fairness can be so emotional because it is processed in the emotional part of the brain.

"The fact that the brain has such a robust response to unfairness suggests that sensing unfairness is a basic evolved capacity," study author Steven Quartz says in a statement.

The study, published in the journal Science, involved 26 men and women between ages 28 to 55 years that faced a real-world moral dilemma concerning 60 orphans at the Canaan Children's Home in Uganda. The orphanage would receive a sum of money that would depend on decisions the subjects made. In the end, $2,279 was donated.

While a functional magnetic resonance imaging machine scanned their brains for peak activity regions, the participants each had about eight seconds to decide how to distribute meals among groups of children in different scenarios.

When the study subjects got to give food to the children, the study participants' orbital frontal cortex, the reward region of the brain, lit up. When instead they took food away, the insula region-- the emotional processor -- was activated.

Quartz suggests that the insula was triggered by the inequity of the choices, but activity varied considerably across subjects, indicating that individual differences in moral sensitivity.