Inside the Minds of Murderers

Impulsive Murderers Much More Mentally Impaired Than Those Who Kill Strategically

The minds of murderers who kill impulsively, often out of rage, and those who carefully carry out premeditated crimes differ markedly both psychologically and intellectually, according to a new study by Northwestern Medicine® researcher Robert Hanlon.
"Impulsive murderers were much more mentally impaired, particularly cognitively impaired, in terms of both their intelligence and other cognitive functions," said Hanlon, senior author of the study and associate professor of clinical psychiatry and clinical neurology at Northwestern University Feinberg School of Medicine.

"The predatory and premeditated murderers did not typically show any major intellectual or cognitive impairments, but many more of them have psychiatric disorders," he said.

Published online in the journal Criminal Justice and Behavior, the study is the first to examine the neuropsychological and intelligence differences of murderers who kill impulsively versus those who kill as the result of a premeditated strategic plan.
  • Compared to impulsive murderers, premeditated murderers are almost twice as likely to have a history of mood disorders or psychotic disorders -- 61 percent versus 34 percent.
  • Compared to predatory murderers, impulsive murderers are more likely to be developmentally disabled and have cognitive and intellectual impairments -- 59 percent versus 36 percent.
  • Nearly all of the impulsive murderers have a history of alcohol or drug abuse and/or were intoxicated at the time of the crime -- 93 percent versus 76 percent of those who strategized about their crimes.
Based on established criteria, 77 murderers from typical prison populations in Illinois and Missouri were classified into the two groups (affective/impulsive and premeditated/predatory murderers). Hanlon compared their performances on standardized measures of intelligence and neuropsychological tests of memory, attention and executive functions. He spent hours with each individual, administering series of tests to complete an evaluation. Hanlon has spent thousands of hours studying the minds of murderers through his research.

"It's important to try to learn as much as we can about the thought patterns and the psychopathology, neuropathology and mental disorders that tend to characterize the types of people committing these crimes," he said. "Ultimately, we may be able to increase our rates of prevention and also assist the courts, particularly helping judges and juries be more informed about the minds and the mental abnormalities of the people who commit these violent crimes."


Story Source:  R. E. Hanlon, M. Brook, J. Stratton, M. Jensen, L. H. Rubin. Neuropsychological and Intellectual Differences Between Types of Murderers: Affective/Impulsive Versus Predatory/ Instrumental (Premeditated) Homicide. Criminal Justice and Behavior, 2013

Comments

Post a Comment

Popular posts from this blog

How the lives of Georgian gaolbirds and highwaymen shaped modern Britain

Image
Writing historical fiction requires solid research of available materials and databases.  The key word here is available.   So news of a new publicly accessible database that allows an author to research a very interesting past era is priceless almost beyond words.   I expect some exciting fiction to come out of this announcement. Here's the story, with a link to the source in the attribution. *  *  *  *  * London Lives, a landmark project led by Professor Bob Shoemaker from the University of Sheffield and Professor Tim Hitchcock from the University of Sussex, has uncovered a mass of extraordinary new evidence which reveals how the lives of thousands of 18th-century poor and criminal Londoners helped shape modern Britain. Based on evidence made available in a publicly available database, the study sheds new light on the everyday lives of thieves, prostitutes, vagrants, highwaymen, con-men, paupers and jailbirds, revealing how their daily fight for survival led to t
Read more

An unexpected way to recover from a breakup

Image
Breaking up is truly hard to do. And recovery from a breakup can be even harder. Your friends may counsel you to put the whole thing out of your mind. But new research suggests that repeatedly reflecting on a break-up -- even through participation in a research study -- actually speeds emotional recovery. "Breakups are ubiquitous -- most adults have experienced at least one in their life -- and are typically very distressing," says Grace Larson of Northwestern University. After studying divorce and breakups for years using longitudinal, multi-method designs, Larson and her then-adviser David Sbarra of the University of Arizona wanted to study whether these research techniques on their own were affecting participants. One concern they had was that the studies could be harming participants, Larson says. "At first glance, it might seem like repeatedly reminding participants that they had just broken up -- and asking them to describe the breakup over and over --
Read more

Greek Bronze Age ended 100 years earlier than thought

Image
Source: www.shef.ac.uk The charred remains of Assiros Toumba in Greece. Writing historical fiction set in the Greek Bronze Age?  Or simply enjoy reading this genre'?  Here's a study you may find interesting. C onventional estimates for the collapse of the Aegean civilization may be incorrect by up to a century, according to new radiocarbon analyses. While historical chronologies traditionally place the end of the Greek Bronze Age at around 1025 BCE, this latest research suggests a date 70 to 100 years earlier. www.weather-forecast.com Archaeologists from the University of Birmingham selected 60 samples of animal bones, plant remains and building timbers, excavated at Assiros in northern Greece, to be radiocarbon dated and correlated with 95.4% accuracy using Bayesian statistical methodology at the University of Oxford and the Akademie der Wissenschaften Heidelberg, Germany. Researcher Dr Ken Wardle says, 'These new results tell a story that is totall
Read more

Mood Instability and Your Characters

Image
You're putting together a character who's mood simply bounces all over the place, happy one moment, in a fit of rage the next.  Researchers at King's College London note that this sort of mood instability is part of a number of mental health disorders.  So how do you structure the personality and behavior of a character like this?  Below is the King's College report, along with a brief description from mentalhealth.com, of typical behavior, sometimes in the extreme, of a person who is very emotionally unstable.  This is offered strictly as a guide for crafting character in fiction - and NOT for the amateur diagnosis of the state of someone's mental health.  That is always best left to trained professionals. Another note about emotionally unstable behavior:  as any parent will tell you, this is how adolescents and teen-agers often behave.  It's a normal part of growing up - but it is a matter of degree .  In the extreme, however, this behavior can be diag
Read more

Remember faces but not names? You got it wrong.

Image
Source:   Daily Excelsior So, you think you're good at remembering faces, but terrible with names? New research has revealed we are actually better at remembering names than faces The cringe-worthy experience of not being able to remember an acquaintance's name leads many of us to believe we are terrible with names. However, new research has revealed this intuition is misleading; we are actually better at remembering names than faces. With the Christmas party season fast approaching, there will be plenty of opportunity to re-live the familiar, and excruciatingly-awkward, social situation of not being able to remember an acquaintance's name. This cringe-worthy experience leads many of us to believe we are terrible at remembering names. However, new research has revealed this intuition is misleading; we are actually better at remembering names than faces. The authors of the study, from the University of York, suggest that when we castigate ourselves f
Read more