sends news that two commonly-prescribed drugs have been shown to influence how the human brain makes moral decisions
. Citalopram is an SSRI used to treat depression, and levodopa is often used to combat Parkinson's disease. A new study (abstract
) asked subjects to set a monetary value on receiving painful electric shocks — for themselves and for others (e.g. "Would you rather endure seven shocks to earn $10 or 10 shocks to earn $15?"). The study found that subjects on citalopram (which affects serotonin levels) were willing to give up more money to reduce shocks, both for themselves and others. Those on levodopa (which affects dopamine levels) made people just as willing to shock others as they were to shock themselves, when those on a placebo tended to be more reluctant to shock others.
[Neuroscientist Molly] Crockett says those effects could suggests multiple underlying mechanisms. For example, excess dopamine might make our brain's reward system more responsive to the prospect of avoiding personal harm. Or it could tamp down our sense of uncertainty about what another person is experiencing, making us less hesitant to dole out pain. Serotonin, meanwhile, appeared to have a more general effect on aversion to harm, not just a heightened concern for another person. Such knowledge could eventually develop drugs that address disorders of social behavior, she says.