MRI scans reveal effect of 'mob mentality' on the brain

All of us will have had direct experience of how cruel humans
can be when we act in groups.

One-to-one interactions are usually governed by a common sense
of humanity. But when ideas like "us" and "them" enter the
equation, things can quickly turn nasty.

Now a new study has shed light on what happens in the brain when we
are part of a group, and it suggests that our brain's sensitivity
to morality is dulled when we are just a cog in a larger
machine.

There are numerous and complementary explanations for why humans
are more susceptible to doing terrible things when they act
en-masse. They broadly fall into three categories: that it is
rational to act in the interest of "us", even it is at the expense
of "them"; that groups provide anonymity and help to diffuse
responsibility; and that we become less aware of our individual
selves and moral identity in a group.

The third explanation is what a team of scientists from MIT,
University of California, Berkeley, and Carnegie Mellon University
set out to explore.

Twenty-three university students were asked to play a game where
a series of personalised messages popped up on a screen in front of
them. Some of the messages were related to social media -- "I have
more than 600 Facebook friends" -- and others alluded to moral
issues like, "I have stolen food from shared refrigerators".

The task was to push a button whenever a social media message
appeared. The students were told they were competing another
student, or group of students, for money and their brain activity
was monitored via MRI while they played.

However, the game was just a distraction. What the researchers
really wanted to monitor was activity in the medial prefrontal
cortex, a part of the brain linked with self-reflection.

When participants were told they were playing in a team, there
was markedly less activity in this part of the brain when moral
messages appeared on screen as opposed to when participants were
told they were playing solo.

What's more, after the game they were asked to select photos of
their opposition to be published along with the paper. Those who
had shown less activity in their medial prefrontal cortex chose
less flattering photos for their opponents than for teammates.

"Importantly, this relationship was specific to moral items,"
the study's authors write in the journal NeuroImage. "There was no
relationship between [photo choice] and [the brain activity]
response to communication items."

What's interesting is that not all participants showed the same
change in brain activity. Some were very strongly affected by
competing in a team, while others were less so. The study didn't
explore why some people might be more susceptible to losing
themselves in a group than others.

"This process alone does not account for intergroup conflict,"
said lead author Mina Cikara in a press release. "Still, these
results suggest that at least in some cases, explicitly reflecting
on one's own personal moral standards may help to attenuate the
influence of 'mob mentality'".

As corny as it sounds, "don't forget who you are," is pretty
sounds advice after all.