- Published: November 30, 1999
All people lie, whether about a friend’s “amazing” haircut or what we actually thought about that book, but whereas most people can control when and what they lie about, others lie repeatedly and compulsively.
In 2005, a study published in the British Journal of Psychiatry found structural differences in the brains of people who lie versus normal individuals. Because pathological lying is not an official diagnosis, researchers used a variety of criteria, including the Psychopathy Checklist-Revised and the DSM-IV, to categorize people’s behavior. They recruited subjects from temporary employment agencies, figuring that liars would be over-represented at these locations.
After taking structural MRIs of both liars and age-matched controls, the scientists found that liars had increased prefrontal white mater volumes and reduced prefrontal grey/white ratios compared with both antisocial controls and normal controls. The comparison to antisocial personality controls was interesting, because lying is often clumped together with antisocial personality disorder. These results, though, suggest that lying arises from a significantly different psychophysiology.
One possible explanation for the structural differences is that increased prefrontal white matter provides the individual with the cognitive capacity to lie. Behavioral research, for instance, indicates that around the time white matter increases significantly in childhood, children become markedly more adept at lying (Paus et al, 2001, McCann, 1998). The scientist suggest that increased prefrontal white matter found in adult liars predisposes them to lying - a very interesting idea!
What causes increased prefrontal white matter? Can it be correlated with developmental factors, such as drug/alcohol abuse during pregnancy, a low-income household, or a criminal parent? How early can these abnormalities be detected, and do they have strong predicative power for future pathological behavior?