The Science of Lying
Jeffrey Arnett, a professor at the University of Maryland, recently published a study that unveiled an interesting fact about college students: on average, they lie to their parents one out of every five interactions. (For some of us, this may be more of a minimum than an average). But this study doesn’t address some more interesting questions: why, neurologically and psychologically, do people – college students or not – lie?
Neurobiologists generally agree that the anterior prefrontal cortex (aPFC) – the part of the brain that is thought to regulate social behavior and decision making – is responsible for deceptive behavior. Scientists aren’t exactly sure how the aPFC causes this behavior, but much of the existing research suggests that activity in one’s aPFC increases when one is being deceitful – in other words, the brain works harder to tell a lie than to tell a truth.
This logical conclusion is well established in the scientific community, but a recent set of studies conducted by the German Institute of Medical Psychology and Behavioral Neurobiology (IMPBN) has scientists worldwide doubting the conventional wisdom. In these studies, volunteers role-played as thieves and pretended to rob a bank. They then participated in a mock interrogation session, during which they were instructed to lie about certain details concerning the “robbery” they had just committed.
During this interrogation, the researchers suppressed the activity levels of each participant’s aPFC with a process called transcranial direct current stimulation (tDCS). They expected the respondents to come up with lies more slowly, but surprisingly, it was significantly easier for respondents with tDCS to lie! This raises a pivotal question: is it actually easier for the brain to lie than to tell the truth?
Researchers haven’t come up with a tidy explanation for this yet (as any neuroscience major will tell you, the brain is hard), but the revelation that the inactivity of the aPFC may spur dishonest behavior may lead to a better understanding of disorders like pathological lying that cause constant, grandiose lying. Researchers are aware that changes in the prefrontal cortex typically accompany lying, and the IMPBN’s findings shed more insight on how to modulate brain activity to suppress deceitful actions.
This research also has implications for an incredibly rare disease known as fantastic confabulation, which causes those afflicted to make up grandiose, implausible stories – and completely believe those stories. In one case, a patient whose arm was paralyzed and who suffered confabulation repeatedly claimed – and truly believed – that she could not move her arm because she had arthritis. This bizarre disorder is thought to be a result of the malfunction of many different parts of the brain, but suppressing the activity of the aPFC to control this disease, as researchers and doctors have tried, may be inadvisable in light of this new research.
It’s clear that, unlike confabulation patients, college students know exactly when they’re lying. But regardless of the psychological reasons that college students – or anyone, for that matter – choose to lie, scientists hope that new insights on how the brain works can help us better understand the complex phenomenon of lying.