If you lie once, you’re probably more likely to lie
again. New research shows that the part of the
brain that is activated during dishonesty
responds less and less as we “get used” to
cheating — and that could make us lie even
more.



There are anecdotes about people cheating more
over time. But there hasn’t been research confirming this biologically until now, says study author Neil Garret , a psychologist at University College London. For a study published today in Nature ,
Garret’s team had participants play a game
where they would sometimes get more money
for lying to their partner. Brain scans of the
participants confirmed that lying can be a
slippery slope: people did lie more over time.
Their brains got desensitized to it, and how much
it was desensitized could predict how much
more someone would lie the next time.



When we deceive someone, the part of the brain
that regulates emotion — called the amygdala —
is activated, and we often feel shame or guilt.
The amygdala also reacts when we see cute
pictures of puppies or very sad photos. We
already knew that when our brains see these
cute or sad photos again and again, the
amygdala reacts less and less every time. Garret
and his team wanted to know if this was true for
lying, too.


The team recruited adults to work with another
person that they didn’t know. The participants
had to look at a picture of a glass jar and then
tell their partner — who was helping the
researchers — how many pennies were in it. At
the end, both would get paid, but sometimes the
participants would get more money if they lied.
(They could lie to help themselves, help their
partners, help both, and so on.) As the
participants played the game, the researchers did
brain scans of some of them. These scans,
called fMRIs, show which regions of the brain
used more oxygen; this is an indicator of brain
activity. The researchers saw that as the
participants continued to lie, the amygdala
reacted less.




Participants in the game also became more
dishonest more quickly when it would benefit just
them and not their partner. And the amygdala
really did activate less as people lied to help
themselves. The participants kept lying to help
themselves even if lying didn’t lead to more
money every single time. This means it’s likely
that people keep lying not because of rational
calculation, but because they become
desensitized..

**ALL OF US GET BOLDER WITH DISHONESTY**




“The reduction in activity in the amygdala can
predict how much people increase dishonesty
subsequently,” adds Garret. Predicting future
behavior didn’t work accurately for everyone, but
the overall trend was there. (The researchers
didn’t track demographic trends of what kind of
person became more used to lying.)











There are some limitations. This study tested a
specific game, so we don’t know exactly what
would happen in other types of situations when
dishonesty is involved. And while the fact that
this was done in a lab meant that the
researchers could control things like who the
participants were working with and how the
game worked, the downside is always that it’s
less clear how much this will apply in the real
world. Brain scans also have to be taken with a
grain of salt, as sometimes they can be
misleading. (One fMRI test showed that a dead
fish had brain activity .) In the study, just
because a part of the brain was less active
doesn’t necessarily mean that people didn’t feel
as bad (and the researchers couldn’t ask
because then that would give away the
experiment).














But Garret says it’s pretty likely that there really
is a slippery slope situation happening. We feel
guilty the first time we cheat on a test, but by
the third time we’re used to it. Now we know
how the mechanism works — not just for people
like Madoff or serial plagiarists that become
more and more bold with their dishonesty, but for
all of us.