Professor of Psychiatry, Department of Academic Clinical Psychiatry, Division of Genomic Medicine, University of Sheffield, The Longley Centre, Norwood Grange Drive, Sheffield S5 7JT, UK. Tel: +44 (0)114 22 61519; fax: +44 (0)114 22 61522; e-mail: S.A.Spence{at}Sheffield.ac.uk
See pp.
320325, this issue.
![]() |
INTRODUCTION |
---|
![]() ![]() ![]() ![]() ![]() |
---|
This study raises a number of intriguing questions. Why should prefrontal structure affect deceptive behaviour? What is the contribution of white matter? How specific (and replicable) are the findings likely to be? What do we mean by pathological lying?
![]() |
WHITE MATTER |
---|
![]() ![]() ![]() ![]() ![]() |
---|
Examples of reduction in prefrontal white matter in neuropsychiatric disease are relatively easy to find. A literature search performed in January 2005, entirely confined to prefrontal white matter volume, revealed approximately 40 records describing volume reductions in schizophrenia (variably replicated, possibly related to chronicity or medication), alcohol dependence (probably confined to clinical samples and older age groups) and attention-deficit hyperactivity disorder. Neither bipolar disorder nor the neuroses have been consistently associated with such changes to date. However, increased prefrontal white matter is rarely reported, neurofibromatosis type 1 providing an exception (Cutting et al, 2002). To my knowledge, this condition is not associated with deception per se, although of course it may have severe consequences for cognitive development. Thus, Yang et als finding of increased prefrontal white matter volume (in community liars) is uncommon among clinical samples.
![]() |
THE LYING BRAIN |
---|
![]() ![]() ![]() ![]() ![]() |
---|
This prompts a question: should a prefrontal white matter abnormality result in more or less, or perhaps better or worse, deception? If deception relies upon cognitive resource, then cognitive deficit should impair deception (as in the case of autism; Sodian & Frith, 1992), while the cognitively advantaged should be good at deceiving. So, is increased white matter likely to impede or facilitate information processing (and, thereby, deception)? Yang et als findings imply that excess prefrontal white matter confers some capacity for deception, akin to an advantage. King & Ford (1988) reached similar conclusions when they found that those with pseudologia fantastica might exhibit superior verbal abilities (despite increased prevalence of neurological abnormality). Such conclusions evoke the stereotypic image of the liar as one who is smooth-tongued and Machiavellian.
Thus, a straightforward interpretation of Yang et als study would conclude that increased prefrontal white matter confers a predisposition to lying, which itself confers a competitive edge in day-to-day life. But there are caveats.
First, we do not know whether the findings reflect cause or effect (whether anatomy drives deception or is driven by its practice). We cannot form a firm conclusion on the basis of cross-sectional data.
Second, the meaning of pathological requires elucidation. While the authors rightly use the term in a very specific way, their criteria differ from those of certain other studies. What is pathological lying? It is not lying per se, as normal people tell lies regularly, often to their nearest and dearest (Vrij, 2001). Lying may, on occasion, be considered altruistic. Not so the lying attributed to those in the study of Yang et al; this is predominantly antisocial lying (e.g. conning and benefit fraud). It seems inherently instrumental (and, hence, akin to malingering). Yet, it differs from the pathological lying described by Ford (1995) and in the Munchhausens literature, where emphasis is placed upon selfdefeating, impulsive or compulsive lying, not associated with tangible personal gain. Hence there may be different types of pathological lying, with that described by Yang et al pertaining to the more antisocial variant.
Third, how accomplished were those described by Yang et al at telling lies? They attended temporary employment agencies, consented to being studied and admitted to lying. This is not very Machiavellian! We might contrast them with those successful social predators who lie and cheat and yet retain enormous influence in the world (the doubting reader might reflect upon Smiths (2002) account of these powerful people). Yang et als findings may be specific to an underprivileged milieu: where a subgroup of unemployed antisocial people resort to deception for instrumental gain but are not necessarily very good at lying.
The study of Yang et al has opened up a new area in the use of neuroimaging technologies to examine aspects of human behaviour, yielding findings that may have profound consequences for the way we view immoral and forensic activity, responsibility and mitigation. Philosophically, they point towards behaviour (and, by extension, morality) that is constrained by biology. It might be remarked that although the science in this area is relatively recent the assumption has been implicit in much forensic psychiatric practice for some time. The very seriousness of this proposition underscores the need for further careful work in this area.
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() |
---|
Cutting, L. E., Cooper, K. L., Koth, C.W., et al
(2002) Megalencephaly in NF1: predominantly white matter
contribution and mitigation by ADHD. Neurology,
59, 1388
1394.
Filley, C. M. (2001) The Behavioural Neurology of White Matter. Oxford: Oxford University Press.
Ford, C.V. (1995) Lies! Lies! Lies! The Psychology of Deceit, pp. 133 146. Washington, DC: American Psychiatric Association.
King, B. H., Ford, C.V. (1988) Pseudologia fantastica. Acta Psychiatrica Scandinavica, 77, 1 6.[Medline]
Raine, A., Lencz, T., Bihrle, S., et al
(2000) Reduced prefrontal grey matter volume and reduced
autonomic activity in antisocial personality disorder. Archives of
General Psychiatry, 57, 119
127.
Smith, J. (2002) Moralities. London: Penguin.
Sodian, B. & Frith, U. (1992) Deception and sabotage in autistic, retarded and normal children. Journal of Child Psychology and Psychiatry, 33, 591 605.[Medline]
Spence, S. A., Hunter, M. D. & Harpin, G. (2002) Neuroscience and the will. Current Opinion in Psychiatry, 15, 519 526.[CrossRef]
Spence, S. A., Hunter, M. D., Farrow, F. D., et al (2004) A cognitive neurobiological account of deception: evidence from functional neuroimaging. Philosophical Transactions of the Royal Society of London Series B, 359, 1755 1762.[CrossRef][Medline]
Vrij, A. (2001) Detecting Lies and Deceit: The Psychology of Lying and Implications for Professional Practice. Chichester: Wiley.
Yang, Y., Raine, A., Lencz, T., et al (2005) Prefrontal white matter in pathological liars. British Journal of Psychiatry, 187, 320 325.[CrossRef]
Received for publication January 24, 2005. Accepted for publication March 7, 2005.
Related articles in BJP: