Mark Stokes is a senior research scientist at the Oxford Centre for Human Brain Activity, University of Oxford. As Head of the Attention Group, his research programme explores the brain mechanisms that control attentional selection for perception, memory, decision-making and conscious awareness. In addition to frontline research, he is also interested in public engagement. In 2012, he launched a neuroscience blog, The Brain Box, to discuss all matters mind and brain, covering research from his own lab as well as latest findings and controversies in the field. He has also been commissioned to contribute blog posts and comments to mainstream news providers, including the Guardian and The Independent. Mark has also appeared in science documentaries, including a Discovery Channel programme on hypnosis and has advised for BBC 1’s Bang Goes the Theory and BBC2’s Horizon. Currently, Mark is working on an article discussing the neuroscience of law and criminal justice, based on David Eagleman’s new book, Incognito. You can follow him on Twitter @StokesNeuro.

On August 1st 1966, Charles Whitman ascended the Tower of the University of Texas Austin and opened fire on innocent bystanders, having already killed his wife and mother. In his apparent suicide note, he wrote:

“I do not really understand myself these days. I am supposed to be an average reasonable and intelligent young man. However, lately (I cannot recall when it started) I have been a victim of many unusual and irrational thoughts”.

He suspected that there was something wrong with his brain, and indeed subsequent autopsy revealed an extremely aggressive tumour that was impinging on brain tissue.

Is it possible that a brain tumour could cause an ordinary person to commit mass murder? Was Whitman really just a victim of circumstance, like the other 14 people that were killed that day simply for being in the wrong place at the wrong time? In his recent book Incognito, neuroscientist David Eagleman explores how neural explanations for criminal behaviour might change the way we think of culpability. He begins by reviewing contemporary theories in the neuroscience of perception, action and awareness, while describing myriad cases of abnormal and/or criminal behaviour caused by identifiable brain abnormalities. Wearing his other hat as Director of the Initiative on Neuroscience and the Law, Eagleman then considers how such causal explanations of behaviour, and misbehaviour, challenge the concept of free will, and common notions of blame and punishment that are deeply rooted in the criminal justice system.

Should a modern judiciary punish people for suffering a tumour that causes them to commit mass murder? Or for exposure to abuse, poverty, violence of war, or any other of the likely causes of subsequent criminal behaviour? Eagleman even considers the classic case of Phineas Gage; surely only the most ruthless moralist would blame Gage for his dramatic personality change – after all, the guy had a 6kg iron rod blasted through his frontal lobe!

The question of blame invariably comes around to the notion of free will, which is notoriously difficult to reconcile within a deterministic framework: given the same initial conditions, exactly the same behaviour will be observed. Our fate is sealed long before we are born. Even if we permit some randomness in the causal chain, such as quantum indeterminacy, that is hardly the kind of freedom that most people hold dear to a sense of agency.

Even a non-physical cause provides little relief from the basic problem. Shifting agency to a non-material entity, such as soul, only relocates the ultimate cause of behaviour. According to the Calvinist view of predestination, for example, we simply play out the hand that we are dealt – by God’s divine will, our souls are either destined for salvation or damnation. Behaviour remains predetermined, albeit by a fuzzy kind of cause.

Despite compelling neuroscientific, philosophical and even religious arguments against the concept of free will, there is no doubt that the sense of free will, and our propensity for blame and punishment, are psychological realities. We certainly feel ownership over our thoughts, preferences, decisions and actions, and we are quick to blame others when they freely act outside society’s rules. Presumably, the psychology of blame and punishment has evolved to keep early societies in order, but are they still relevant today? What happens when we can identify clear external factors that have caused bad behaviour, such as the tamping iron responsible for Phineas Gage’s frontal lobotomy?

Eagleman argues that a punitive legal system panders to our sense of moral justice. The economy of crime, blame and punishment is simply not rational, even if deeply felt. The more we understand about the neuroscience of behaviour, the more the idea of free will, and related notions of moral blame, start to evaporate.

Accordingly, legal reform should focus on crime prevention. Criminals should be prevented from reoffending by rehabilitation and risk-assessed prison terms. The concept of risk-based detention takes an actuarial approach to custodial sentencing, in which explanatory variables are used to predict future behaviour and likelihood of recidivism. This approach only makes sense within a non-retributive context; within a punitive framework, the guilty will actually be punished more severely for crimes that can be more easily explained by case history (e.g., deprived childhood, history of abuse, etc). It hardly seems fair to mete out harsher punishments to people because they have suffered more damaging external circumstances (i.e., risk factors). But fairness is the wrong metric – risk-assessed sentencing must consider prison as a practical means to keep people out of harm’s way during a period of likely reoffending.

Eagleman is also careful to avoid seeming to be soft on crime. The success of any such reform in US criminal justice critically depends on bipartisan support. Therefore, he goes to considerable lengths to stress that a rational approach does not mean “letting criminals get away with it”. This nod to conservatism may be a strategic necessity, but it essentially promises that the rational approach will also be punishing. By coincidence, or by design? What if the empirical data suggest that the most rational solution for society was effectively to “let prisoners get away with it”? To what extent can we bend the rational approach to accommodate the human penchant for blame?

Reform toward a legal system focused more on crime prevention and rehabilitation than punitive justice is perhaps less radical to many non-US audiences, but crime and punishment remain controversial political issues in all corners of the world. A rational case for a utilitarian approach to law can probably be made without recourse to neuroscience. Furthermore, we probably don’t even need neuroscience to debunk irrational notions of free will that underpin blame and punishment. However, neuroscience certainly provides a steady supply of graphic examples to challenge our deep psychological conviction that we freely choose our own actions. The more we learn about the brain, the more we can identify the causes of behaviour, and the abnormalities that cause abnormal behaviour, including criminal acts. Will we continue to punish each other for evidently pre-determined transgressions?