"The Neurobiology of Evil"


This is a comment on a recent post from bigthink.com by John Cookson.

The term "nature versus nurture" was coined by Charles Darwin's cousin, Francis Galton. John Locke famously wrote about the "tabula rasa" or blank slate, first espoused by Aristotle, a concept that individuals are born without any built-in mental content. Their legacy, the overly simplistic binary that divides DNA and personal experience, is still used today.


Brain imaging technology is so advanced that it is possible to extract images from a person's mind and display them on a computer monitor. Japan's ATR Computational Neuroscience Laboratories announced the fMRI's new potential in 2008. Mapping the blood flow changes that occurred in the cerebral visual cortex as subjects viewed a set of mapped images, a computer learnt the blood flow associations with the "map" view of the images. The system was then able to recreate a new set of images based solely on the subject's brain activity.
Hoping to use the technology to better understand dreams, hallucinations and even emotions, the system, in it's primitive stages, may in as little as 10 years, be able to accurately read and reproduce the thoughts of an individual. Similar technology has been designed (not yet fully functional) to help paralysed people speak. Using MRI and experimental microECoG electrodes implanted beneath the skull to read speech signals from the brain, University of Utah scientists have been able to translate these signals into words.

Recently, Michael Stone, professor of clinical psychiatry at Columbia University, released "The Anatomy of Evil", the latest in the argument towards a biological basis for criminality. Using MRI and PET scans to observe the limbic system and within, the amygdala, the functioning of the emotion, motivation, fear and pleasure centres of the human brain have been observed. Murderers and other violent criminals have shown to have amygdalae that are smaller or don't function properly, and usually display "significantly higher levels of antisocial personality, psychopathy, arrests and convictions compared with controls."
An inability to read the emotions in others, a lack of empathy, has long been associated with psychiatric disorders and criminality, but until recently, has not been directly observable. Now it is believed that "evil" is directly observable. Laws are being changed and new branches, neurolaw and neuroethics, are becoming more widely accepted.

Further down the rabbit hole, new research has identified seven genes that are linked to antisocial or aggressive behaviour, MAOA, 5HTT, BDNF, NOTCH4, NCAM, tlx and Pet-1-ETS, genes that are also thought to affect the way brain growth is organised.


The Brain That Changes Itself, a book investigating the history and implications of research into neuroplasticity, argues that every thought an individual has changes his/her neural substrate. With slightly too much psychoanalytic emphasis, this book is an interesting introduction to research that changed the course of neuroscience less that 20 years ago. Patterns formed in childhood, addictions, even "irreversible" degradation (stroke, ageing); the external influences that physically alter the neural maps of the brain, can be changed.




A genetic influence in aggression, structural change by repeated action, broken brains as legal indicators; have we come any closer to the question of "nature versus nurture"? Yes, but the answer is invariably further away. The problems, however, are closer and more numerous than ever. Although legal defences or prosecutions are not commonplace, nor is genetic testing for eugenic babies, the water is becoming muddier.

With knowledge in the area of "evil" growing more complex and intricate, but the terminology remaining over-simplified and inaccurate, we will face a greater problem of how valid information is received and used in the future. Scientists need to be dispelling oversimplified binaries rather than facilitating them. Science writers need to be even more careful. I continue to read quotes from scientists and tag lines from science writers that promote phrasal clichés and dichotomous thinking. "Nature versus nurture" and "good and evil" seem to be two that are hot topics in both legal and biological neuro-arenas; whose better intentions are condensed into afterthoughts in major newspapers that read, Science Discovers Genetic Basis for Evil. Science did not.
Let's not propagate tired clichés and deny the complexity of new information or one day we will find ourselves with law courts using labyrinthine language and involute evidence and their juries still operating with "Brain Scans Show Evil".