Conservatives--particularly
tough-on-crime, pro-military conservatives--have a more pronounced
startle reflex, measured by eye-blink length after hearing a sudden loud
noise. Furthermore, when showed threatening images--maggots in an open
wound, a large spider on someone's face--conservatives displayed a
greater galvanic skin response, caused by subliminal increases in sweat
gland activity. These traits are linked to high activity in the
amygdala, center of emotional processing and seat of the fear response.
Liberals displayed these reactions as well--the fight-or-flight response
is universal--but in conservatives, it was stronger, faster, and more
pervasive. This also explains why liberals who are placed under stress,
time pressure, or emotional duress are more likely to endorse
conservative viewpoints they would not have otherwise espoused.
And
then there are the liberals and the anterior cingulate cortex, or ACC.
Its role in the brain is somewhat more complicated, but there is still
general scientific consensus that it is involved in error detection and
conflict monitoring, and ultimately cognitive control. Consider a 2007
work published in
Nature Neuroscience,
one of the earliest political neuroscience studies. The researchers
hypothesized that liberals have more active ACCs, since they are more
flexible and intellectually innovative, and more tolerant of
uncertainty. Then they proved as much by having liberals and
conservatives perform a classic test for conflict monitoring, of the
sort that the ACC is thought to govern.
It's called a "Go-No-Go"
task: Study subjects are put in a situation where they are required to
quickly tap a keyboard when they see "M" on screen--and become
habituated to doing so. But one fifth of the time, the screen instead
flashes a "W," and respondents have to quickly change their behavior and
not tap the keyboard. Liberals performed better at the task--they were
less likely to commit a 'D'oh!' and tap the keyboard at the wrong
time--and they also showed more anterior cingulate cortex activity when
engaging in the corrective response. This study was subsequently
replicated by another research team, using a Canadian sample, who also
linked more brain firing in the task to egalitarianism, and less firing
to right-wing authoritarianism.
It is not difficult to interpret
this finding: Liberal's greater anterior cingulate cortex activity
indicates their greater cognitive flexibility and willingness to update
and change their beliefs and responses vis-a-vis changing cues and
situations.