A study by Ruff, Ugazio and Fehr (2013) published online this week suggests that an electrical current directed toward a patch of the brain on the right side of the head, the right lateral prefrontal cortex (rLPFC), can influence compliance with social norms. The scientists show that the rLPFC is involved in voluntary and sanction based norm compliance, and that both of these types of compliance can be modulated by changing the neural excitability of this brain region using transcranial direct current stimulation (tDCS).
The scientists had the subjects play a money-sharing game (usually employed in studies assessing altruism, cooperation and fairness in humans) in which participants could decide whether to: a) share their money with another player who received less without risk (baseline round) or b) share less money and risk receiving sanctions (aka have their money taken away) by the other player (punishment round). Participants played this game with real money while a positive, negative, or sham (placebo) electrode was placed directly over their rLPFC. Normally, when a player is undergoing the punishment round, they were more likely to share more money with another player. However, depending on the direction of the current, participants in such a game shared more or less money, apparently becoming more or less sensitive to the social norm of being fair. Furthermore, activating the rLPFC with tDCS only made people more norm-compliant under conditions in which the subject faced a risk of punishment, suggesting that the rLPFC allows participants to flexibly adjust their behavior to the presence or absence of punishment threats.
Culotta, Elizabeth. (October 4, 2013). Brain Stimulation Sparks Machiavellian Choices.
Ruff, C.C., Ugazio, G. and Fehr E. (2013). Changing Social Norm Compliance With Noninvasive Brain Stimulation. Science.