How lying takes our brains down a 'slippery slope'

October 24, 2016
Credit: Wikimedia Commons

Telling small lies desensitises our brains to the associated negative emotions and may encourage us to tell bigger lies in future, reveals new UCL research funded by Wellcome and the Center for Advanced Hindsight.

The research, published in Nature Neuroscience, provides the first empirical evidence that self-serving lies gradually escalate and reveals how this happens in our brains.

The team scanned volunteers' brains while they took part in tasks where they could lie for personal gain. They found that the amygdala, a part of the brain associated with emotion, was most active when people first lied for personal gain. The amygdala's response to lying declined with every lie while the magnitude of the lies escalated. Crucially, the researchers found that larger drops in amygdala activity predicted bigger lies in future.

"When we lie for , our amygdala produces a negative feeling that limits the extent to which we are prepared to lie," explains senior author Dr Tali Sharot (UCL Experimental Psychology). "However, this response fades as we continue to lie, and the more it falls the bigger our lies become. This may lead to a 'slippery slope' where small acts of dishonesty escalate into more significant lies."

The study included 80 volunteers who took part in a team estimation task that involved guessing the number of pennies in a jar and sending their estimates to unseen partners using a computer. This took place in several different scenarios. In the baseline scenario, participants were told that aiming for the most accurate estimate would benefit them and their partner. In various other scenarios, over- or under-estimating the amount would either benefit them at their partner's expense, benefit both of them, benefit their partner at their own expense, or only benefit one of them with no effect on the other.

When over-estimating the amount would benefit the volunteer at their partner's expense, people started by slightly exaggerating their estimates which elicited strong amygdala responses. Their exaggerations escalated as the experiment went on while their amygdala responses declined.

"It is likely the brain's blunted response to repeated acts of dishonesty reflects a reduced emotional response to these acts," says lead author Dr Neil Garrett (UCL Experimental Psychology). "This is in line with suggestions that our signals aversion to acts that we consider wrong or immoral. We only tested dishonesty in this experiment, but the same principle may also apply to escalations in other actions such as risk taking or violent behaviour."

Dr Raliza Stoyanova, Senior Portfolio Developer, in the Neuroscience and Mental Health team at Wellcome, said: "This is a very interesting first look at the brain's response to repeated and increasing acts of dishonesty. Future work would be needed to tease out more precisely whether these acts of dishonesty are indeed linked to a blunted emotional response, and whether escalations in other types of behaviour would have the same effect."

Explore further: Learning to turn down your amygdala can modify your emotions

More information: Nature Neuroscience, nature.com/articles/doi:10.1038/nn.4426

Related Stories

Learning to turn down your amygdala can modify your emotions

September 12, 2016
Training the brain to treat itself is a promising therapy for traumatic stress. The training uses an auditory or visual signal that corresponds to the activity of a particular brain region, called neurofeedback, which can ...

New neural pathway for fear found in mice

September 6, 2016
(Medical Xpress)—A team of researchers with the Chinese Academy of Sciences has found that there is a previously unknown neural pathway in the mouse brain that leads from the lateral amygdala to the auditory cortex. In ...

Changes in brain networks may help youth adapt to childhood adversity

July 5, 2016
A new study in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging reports a neural signature of emotional adaptation that could help researchers understand how the brain adapts to childhood adversity and predict ...

After a sip of milkshake, genes and brain activity predict weight gain

May 20, 2015
The way the brain responds while sipping a delicious milkshake can predict who will gain weight and who will not—but only if the individual has just eaten and has a certain genetic profile, a new brain imaging study by ...

Researchers temporarily turn off brain area to better understand function

July 21, 2016
Capitalizing on experimental genetic techniques, researchers at the California National Primate Research Center, or CNPRC, at the University of California, Davis, have demonstrated that temporarily turning off an area of ...

Emotion dysregulation in borderline personality disorder: A problem of too much drive and too little control?

January 13, 2016
Borderline personality disorder (BPD) is a diagnostic label applied to people who have problems regulating emotional mood swings. This emotional instability leaves such individuals vulnerable to emotional upheaval that puts ...

Recommended for you

Researchers find monkey brain structure that decides if viewed objects are new or unidentified

August 18, 2017
A team of researchers working at the University of Tokyo School of Medicine has found what they believe is the part of the monkey brain that decides if something that is being viewed is recognizable. In their paper published ...

Artificial neural networks decode brain activity during performed and imagined movements

August 18, 2017
Artificial intelligence has far outpaced human intelligence in certain tasks. Several groups from the Freiburg excellence cluster BrainLinks-BrainTools led by neuroscientist private lecturer Dr. Tonio Ball are showing how ...

Study of nervous system cells can help to understand degenerative diseases

August 18, 2017
The results of a new study show that many of the genes expressed by microglia differ between humans and mice, which are frequently used as animal models in research on Alzheimer's disease and other neurodegenerative disorders.

How whip-like cell appendages promote bodily fluid flow

August 18, 2017
Researchers at Nagoya University have identified a molecule that enables cell appendages called cilia to beat in a coordinated way to drive the flow of fluid around the brain; this prevents the accumulation of this fluid, ...

Researchers make surprising discovery about how neurons talk to each other

August 17, 2017
Researchers at the University of Pittsburgh have uncovered the mechanism by which neurons keep up with the demands of repeatedly sending signals to other neurons. The new findings, made in fruit flies and mice, challenge ...

Neurons involved in learning, memory preservation less stable, more flexible than once thought

August 17, 2017
The human brain has a region of cells responsible for linking sensory cues to actions and behaviors and cataloging the link as a memory. Cells that form these links have been deemed highly stable and fixed.

4 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

Zzzzzzzz
5 / 5 (1) Oct 24, 2016
Donald Trump's amygdala atrophied 65 years ago
baudrunner
5 / 5 (1) Oct 24, 2016
Their exaggerations escalated as the experiment went on while their amygdala responses declined.
Yah, I know. It's called habituation. Habituation and the tendency to continue "pushing the envelope" occurs also in addictive drug abuse, with the body naturally needing larger and larger doses to get the same effect. It's from the same box.
freeiam
not rated yet Oct 24, 2016
That must be a joke, can you repeat that: "Funded by Wellcome and the Center for Advanced Hindsight."
FredJose
not rated yet Oct 25, 2016
Also known as being "given over to their sins", i.e. habituation as baudrunner said.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.