As the subjects played the game, the scientists scanned their brains.
They looked at the brain's"pleasure center,
which controls how good people feel.
When most subjects donated money to a charity,
their pleasure nters lit up on the brain scan.
Some even lit up when the subjects were taxed on their donation.
Both results suggest that the brain's pleasure center is rewarded for altruistic acts.
In addition, the more people donated the more their pleasure centers lit up. For some,
the pleasure center lit up more when the computer gave the charity extra money