Unit 11

What makes someone a psychopath?

Up to this point we have seen that the human species evolved to be psychologically flexible -- we respond to our social environment in ways that can lead to both good and evil, from every day acts of small kindness to unimaginable destruction.  So what happens when the brain we inherit from our ancestors is "different" in that the parts responsible for empathy and self-control do not operate like a "normal" (average) brain?  How do these genetic differences interact with our environment and lived-experiences?  Could these random variations in brain function ever be advantageous enough to be selected for by evolution?  If so, why aren't all humans psychopaths?  Perhaps there is no better way to delve deeper into the role of nature and nurture than to explore the brains and behavior of psychopaths. 

11-A: The Brains of Psychopathic Killers

• What area was found to be damaged among the brains of psychopathic killers that Fallon studied?

• What is the interaction between the MAO-A gene (which we've already learned about) and exposure to violence?  Review what we learned about the gene's effect on levels of serotonin and how that neurotransmitter influences thought and behavior.

11-B: Diagnosing Psychopathy

• How would you generally describe someone whose disposition would lead to them being described as a psychopath?

  • • What does the research on recidivism rates and predictors say for adults and juveniles?

    • How do the dispositional characteristics vary by primary and secondary psychopathy?

• If the characteristics of psychopathic brains can be inherited, why might evolution have selected for them?  What advantages might these traits have provided in the context of survival and reproduction?

• How might natural and sexual selection have limited the extent and frequency with which those genes were expressed.  That is, if there was something adaptive about the traits associated with psychopathy, why does less than 1% of the human population demonstrate "full clinical manifestations" of it?

  • • Relating this back to what we learned about the evolution of homicidal adaptations, how would tendencies to shun and punish true psychopaths have been selected for by the antagonistic co-evolution of anti-homicidal adaptations? 

• What is the difference between primary and secondary psychopathy?  What category of symptoms is each type associated with?

• What are the four categories of symptoms?  Be prepared to provide at least two examples of specific items on Hare's Checklist (PCL-R) for each factor.

  • • How is the checklist scored?

    • What score is necessary in order to be clinically considered a psychopath?

Going beyond an examination of dead brains, researchers now have the ability to study the structure and activity of brains via functional magnetic resonance imaging (fMRI).  Needless to say, studying neuropsychology can get pretty complex, especially at maximum security prisons, but the following article summarizes some key concepts and findings from years of research without getting too far into the technical details.

What does comorbid or comorbidity mean?

Comorbidity refers to a correlation between two diagnoses.  So, for example, when we look at all of the individuals who are diagnosed with Condition A, we tend see higher than average rates of diagnoses with Condition B.  We would say that Conditions A and B are comorbid -- it is not uncommon for someone to be diagnosed with both.

11-C: The Neurobiology of Psychopathy

• Describe in detail the genetic, structural and chemical differences between a psychopathic brain and a normal brain.

  • Gene - MAOA

  • Structures (locate on a diagram, describe its function and the nature of the difference)

    • Amygdala

    • Orbital/Prefrontal cortex

    • Paralimbic system

  • Chemicals – Serotonin & dopamine

READ: Continue with the sections on Neurobiological Models of Psychopathy, Recent Neuroimaging and Psychopathology, Concluding Remarks, and Box 2.

Don’t worry too much about the details in the section of the extended paralimbic structures, read it to get the overall sense of the evidence that these additional areas are involved.

11-D: ASPD - A Milder Version?

• What are the four diagnostic criteria for Antisocial Personality Disorder?

  • Be prepared to describe at least four of the seven sub-features for one of them and give examples of things you might look for in a person's history.

  • Be clear about how age and time are involved.

READ: Antisocial Personality Disorder DSM-5 301.7 (F60.2)

Closing Thoughts...

We started this course with exploring the tension between the influences of disposition vs. situation, and more broadly, of nature and nurture.  We've since seen how certain characteristics may have evolved because they increased fitness, including a latent capability of inflicting some costs on others.  And at extremes, with the darkest (but smallest) segment of the human species, we've now seen how the intersection of nature and nurture can create people capable of unlimited evil.

If you're interested in learning more...

How does psychopathy related to the way people understand and think about moral dilemmas?

READ: Abstract: Psychopathic Traits and Utilitarian Moral Judgment Revisited