Telling small lies causes the brains of liars to become disensitised to lying, new research reveals.
Neurologically, with each lie it becomes progressive easier to tell bigger and bigger lies.
The negative emotions that usually accompany lying reduce with repeated lying, the study found.
Dr Tali Sharot, who led the study, explained:
“When we lie for personal gain, our amygdala produces a negative feeling that limits the extent to which we are prepared to lie.
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.”
Brain scans of liars
The results come from a series of brain scans carried out while people had the opportunity to lie for personal gain.
Repeated liars found it easier and eaiser to tell bigger lies later on.
Dr Neil Garrett, the study’s first author, said:
“It is likely the brain’s blunted response to repeated acts of dishonesty reflects a reduced emotional response to these acts.
This is in line with suggestions that our amygdala 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, of the Wellcome Trust, 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.”
The study was published in the journal Nature Neuroscience (Garrett et al., 2016).
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