More threads by David Baxter PhD

David Baxter PhD

Late Founder
Bad to the bone: Altered connections in the brains of psychopaths
Wiring the Brain Blog
Monday, February 8, 2010

The manipulative con-man. The guy who lies to your face, even when he doesn?t have to. The child who tortures animals. The cold-blooded killer.

Psychopaths are characterised by an absence of empathy and poor impulse control, with a total lack of conscience. About 1% of the total population can be defined as psychopaths, according to a detailed psychological profile checklist. They tend to be egocentric, callous, manipulative, deceptive, superficial, irresponsible and parasitic, even predatory. The majority of psychopaths are not violent and many do very well in jobs where their personality traits are advantageous and their social tendencies tolerated. However, some have a predisposition to calculated, ?instrumental? violence; violence that is cold-blooded, planned and goal-directed. Psychopaths are vastly over-represented among criminals; it is estimated they make up about 20% of the inmates of most prisons. They commit over half of all violent crimes and are 3-4 times more likely to re-offend. They are almost entirely refractory to rehabilitation. These are not nice people.

So how did they get that way? Is it an innate biological condition, a result of social experience, or an interaction between these factors? Longitudinal studies have shown that the personality traits associated with psychopathy are highly stable over time. Early warning signs including ?callous-unemotional traits? and antisocial behaviour can be identified in childhood and are highly predictive of future psychopathy. Large-scale twin studies have shown that these traits are highly heritable ? identical twins, who share 100% of their genes, are much more similar to each other in this trait than fraternal twins, who share only 50% of their genes. In one study, over 80% of the variation in the callous-unemotional trait across the population was due to genetic differences. In contrast, the effect of a shared family environment was almost nil. Psychopathy seems to be a lifelong trait, or combination of traits, which are heavily influenced by genes and hardly at all by social upbringing.

The two defining characteristics of psychopaths, blunted emotional response to negative stimuli, coupled with poor impulse control, can both be measured in psychological and neuroimaging experiments. Several studies have found decreased responsiveness of the amygdala to fearful or other negative stimuli in psychopaths. They do not seem to process heavily loaded emotional words, like ?rape?, for example, any differently from how they process neutral words, like ?table?. This lack of response to negative stimuli can be measured in other ways, such as the failure to induce a galvanic skin response (heightened skin conduction due to sweating) when faced with an impending electrical shock. Psychopaths have also been found to underactivate limbic (emotional) regions of the brain during aversive learning, correlating with an insensitivity to negative reinforcement. The psychopath really just doesn?t care. In this, psychopaths differ from many people who are prone to sudden, impulsive violence, in that those people tend to have a hypersensitive negative emotional response to what would otherwise be relatively innocuous stimuli.

What these two groups have in common is poor impulse control. This faculty relies on the part of the brain called the prefrontal cortex, most particularly the orbitofrontal cortex. It is known that lesions to this part of the brain impair planning, prediction of consequences, and inhibition of socially unacceptable behaviour ? the cognitive mechanisms of ?free won?t?, rather than free will. This brain region is also normally activated by aversive learning, and this activation is also reduced in psychopaths. In addition, both the prefrontal cortex and the amygdala show substantial average reductions in size in psychopaths, suggesting a structural difference in their brains.

These findings have now been united by a recent study that directly analysed connectivity between these two regions. Using diffusion tensor imaging (see post of August 31st 2009), Craig and colleagues found that a measure of the integrity of the axonal tract connecting these two regions, called the uncinate fasciculus, was significantly reduced in psychopaths. Importantly, connectivity of these regions to other parts of the brain was normal. These data thus suggest a specific disruption of the network connecting orbitofrontal cortex and amygdala in psychopaths, the degree of which correlated strongly with the subjects? scores on the psychopathy checklist.

All of these findings are pointing to a picture of psychopathy as an innate, genetically driven difference in connectivity between parts of the brain that normally drive empathy, conscience and impulse control. Not a fault necessarily, and not something that could be classified as a disease or that is always a disadvantage. At a certain frequency in the population, the traits of psychopathy may be highly advantageous to the individual.

This conclusion has serious ethical and legal implications. Could a psychopath mount a legal defense by saying ?my brain made me do it?? Or my ?genes made me do it?? Is this any different from saying my rotten childhood made me do it? Psychopaths know right from wrong ? they just don?t care. That is what society calls ?bad?, not ?mad?. But if they are constitutionally incapable of caring, can they really be blamed for it? On the other hand, if violent psychopaths are a continuing danger to society and completely refractory to rehabilitation, what is to be done with them? Perhaps, as has been proposed in the UK, people with the extreme psychopathic personality profile (or maybe in the near future even a specific genetic profile?) should be monitored or segregated even before they commit a crime.

While it is crucial that these debates are informed by good science, these issues have no clear-cut answers. They will be resolved on a pragmatic basis, weighing the behaviour that society is willing to tolerate versus the rights of the individual, whatever their brains look like, to define their own moral standards.

Reference

Craig, M., Catani, M., Deeley, Q., Latham, R., Daly, E., Kanaan, R., Picchioni, M., McGuire, P., Fahy, T., & Murphy, D. (2009). Altered connections on the road to psychopathy. Molecular Psychiatry, 14 (10), 946-953
 

Hermes

Member
An excellent article.

How complex and problematic to work out the whys and wherefores of this disorder.

I read somewhere that the figure is closer to 5% of the population. Yes, the psychopath does not care, but then maybe s/he can't care, if there are brain defects as described in the article, or if the problem is genetic. It is the person's makeup. Some people have epilepsy, for example, and that is not their fault either. Or some have blue eyes, others brown eyes, black hair. Genetically determined.

The problem is the scale of the harm caused by psychopaths (leaving aside those psycopaths who are killers).

An idea was floated in the U.K. of having a "psychopath register", but it seems Parliament flatly refused to pass any law allowing this.

Hermes

Psychopathic behavior on the other hand is rational, it represents an informed choice, a premeditated strategy to act in way that serves as an effective means to an end. As Robert Hare states:

'Psychopaths are social predators who charm, manipulate, and ruthlessly plow their way through life, leaving a broad trail of broken hearts, shattered expectations, and empty wallets. Completely lacking in conscience and in feelings for others, they selfishly take what they want and do as they please, violating social norms and expectations without the slightest sense of guilt or regret'.

Hare is explicit in his use of the term because he feels that it encapsulates his belief that the condition is a result of psychological, biological and genetic factors.

Just wanted to add this:

The most influential modern clinical description of psychopathy was provided by psychiatrist Hervey Cleckley in a famous work, The Mask of Sanity (1976 [1941]). Cleckley observed that psychopaths, unlike people with major mental disorders such as schizophrenia, can seem quite normal and even charming, thus earning the descriptive term for the condition "mask of sanity." Psychopaths do not suffer from grossly psychotic symptoms, such as hallucinations or delusions, unless they also suffer from another major mental disorder. But people who lack empathy and guilt, who are willing to manipulate, lie, or cheat without hesitation or remorse to achieve their own ends, are so interpersonally and behaviorally abnormal that characterizing the condition as a disorder seems justifiable.
 
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David Baxter PhD

Late Founder
I read somewhere that the figure is closer to 5% of the population.

Any of these are really only estimates. It depends on who is doing the estimate, and why, and what definition is being used for psychopathy.

The problem is the scale of the harm caused by psychopaths (leaving aside those psycopaths who are killers).

The question is how many psychopaths learn to channel their traits into business and industry, etc., and therefore never run afoul of the law at all because they get everything they want without that. Psychopaths don't necessarily set out to commit criminal acts. They just want what they want now and they are willing to do whatever is necessary to get it. Some of them manage to do that legally; some don't.

An idea was floated in the U.K. of having a "psychopath register", but it seems Parliament flatly refused to pass any law allowing this.

Good. Again, given the definitional and predictive problems, I don't think such a register would ever be workable.
 

Hermes

Member
Well, yes, David. No, many of them do not fall foul of the law. I was thinking more of the misery and destruction caused by psychopaths in a spousal/family setting. I think there is a book called "The psychopath next door".

Being glib, superficially charming and apparently normal at first (rather like those with NPD, it has to be said), they enmesh their victim, and there is actually no need for them to murder the "victim". They murder the victim's soul, and often the victim herself will lose her (or his) mind and in some cases kill her/himself.

I think these are the really dangerous psychopaths, who wreck lives, cause untold hurt to nearest and dearest, to their children, because they have no empathy.

I don't think fitting psychopaths with a tag would work either. After all one only finds out what they are after the fact, so to speak.

I don't really know the ins and outs of how statistics are drawn up. But I suppose for a layperson like me, a psychopath is either a psychopath, or s/he isn't.

Hermes
 

David Baxter PhD

Late Founder
Therein lies the problem: We all think we know one when we see one but how does one measure that? Hare's scale, for all its publicity, really only measures criminal tendencies and acts, not the core personality factor(s).

Generally, we identify a psychopath after the fact - when s/he has done something outrageous.

And not all of them are even necessarily domestic abusers, not even the ones who commit outrageous acts outside the family.
 

Hermes

Member
Well, well, well!!

Nothing like a different (and maybe insightful) take on this thorny subject.

Sympathy for the devil: On compassion for total jerks | Psychology Today

Excerpt:

Here you're really torn, half-sympathetic, half-vengeful; half selfless, half self-protective. And he's no help. He won't admit his meanness originates in fear. He practically directs you to treat him as a nasty SOB. Half of you wants to take him at his word. And half of you thinks his denial is all the more sign that he's afraid. And what do you do with the fearful? Well, you shouldn't fight them, should you? That only stirs greater fear.

Will he soften with your kindness? If so, your kindness will have proven worth it. If not, your kindness will only encourage him to be that much meaner to you. But if instead of showing kindness you draw the line and fight back, showing him he can't push you around, he might back down—or you might provoke even more fear, making him that much meaner.

This is not an uncommon situation.
 
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