The Molecule of More

THE MOLECULE OF MORE

bathroom signs that say “Employees must wash hands before returning

to work” are billboards for the Republican Party.

NEUROCHEMICAL MODULATION

OF MORAL JUDGMENT

Drugs work, too. Scientists can make people behave more like conser-
vatives by giving them medication that boosts the H&N neurotransmit-
ter serotonin. In one experiment, participants were given a single dose
of the serotonergic drug citalopram, commonly used to treat depres-
sion.^3 After taking the medication, they became less focused on the
abstract concept of justice and more focused on protecting individuals
from harm. This was demonstrated by their performance in something
called the “ultimatum game.” Here’s how it works.
There are two players in the ultimatum game. One player, called
the proposer, is given a sum of money (e.g., $100) and told to share
it with the  other player, who  is  the  responder. The  proposer can  offer
the responder as much or as little as she likes. If the responder accepts
the  proposer’s offer, they both keep the  money. On  the  other hand,
if the  responder rejects the  offer, neither player gets  anything. It’s  a 
one-shot game. Each player has only one chance.
A  perfectly rational responder would accept any  offer, even $1.  If she 
accepts the  offer, she’s financially better off  than before. But if she rejects
the  offer, she gains nothing. Therefore, rejecting any  offer, no  matter how
small, is  contrary to  her  financial self-interest. Yet  in  reality, low  offers are
rejected because they  offend our  sense of fair  play. A  low  offer makes us 
want to  punish the  proposer—teach her  a  lesson by  inflicting financial

3 Just one dose of a serotonergic antidepressant isn’t enough to influence mood.

It usually takes a few weeks of daily dosing to see an effect. The first dose makes

the level of serotonin in the brain go up, but after a few weeks of treatment things

become more complicated. By the time the depression starts to lift, the brain

has adapted to the medication in such a way that the serotonin system is more

active in some places and less in others. No one really knows how antidepressants

improve mood.