Our Mission

The Time is Now

Neuroscience is a young field, but it has already produced many profound and beguiling discoveries about how the human brain works. While distant developments are hard to predict, it is expected from research that is already underway or being planned that our knowledge of brain functions will expand rapidly during the next few decades.

This new knowledge will increase our understanding of actions that our laws regulate and of attitudes that our laws reflect. How we apply this knowledge can have a major impact on the future of our legal system. With informed and cautious reform, our justice system could have more accurate predictions, more effective interventions, and less bias. Society could have less crime and fewer people in prisons. However, by ignoring or failing to integrate neuroscience properly, we could end up with a legal system that is worse off as a result of unreliable evidence that could send the wrong people to prison and because of widespread skepticism throughout society about law’s basic assumptions.

To avoid such dangers and to improve our legal system, neuroscientists need to understand law, and lawyers need to understand neuroscience. This training has barely begun. A few recent scholarly efforts have brought together neuroscientists and lawyers (Garland 2004, Zeki and Goodenough 2006). (The introduction to Garland 2004 provides a nice survey of the history and current state of law and neuroscience. On related developments in neuroethics, see Marcus 2002, Gazzaniga 2005, and Illes 2006.) Still, this rapidly emerging field is insufficiently theorized and researched. And without a solid, mutual understanding of each others’ fields, lawyers cannot respond rationally to developments in neuroscience, and neuroscientists cannot properly advise lawyers or even recognize the legal relevance of their research.

At present, no systematic program exists to address the difficult legal questions that will inevitably and quickly arise as neuroscience progresses in its ability to understand and manipulate behavior. We need such a program now.

An Overview of Law and Neuroscience

Neuroscience is on the brink of discovering how our brains enable or affect our minds and behaviors. During the last two decades, neuroscientists have developed powerful tools to investigate the neural activity underlying elementary aspects of behavior, such as color and form perception. Recently they have extended their work to encompass higher levels of cognition, including language, memory, and executive control. Planning, reasoning, error detection, and subtle influences of context on human thought and behavior are all now amenable to experimental investigation. This cognitive neuroscience revolution has extended in the last decade to other key areas, such as emotion regulation and social behavior. It has also had profound effects on many related fields from child development to cognitive and social psychology and, more recently, economics, as witnessed by the emerging field of neuroeconomics. In parallel with insights into normal behavior, modern neuroscientific tools have helped us make tremendous advances in understanding, diagnosing, and treating many devastating psychiatric and neurological syndromes from depression to epilepsy.

We know which brain regions monitor our behaviors, which brain regions regulate our emotions, and what happens when these regions are disconnected. We know the network of brain regions that underlie our unique ability to perceive the thoughts of other people, and the critical role that these brain processes have in our social interactions. Not only have we learned a great deal about how the brain perceives objects, maintains attention, assembles language, sets goals, plans actions, and detects cheaters, we are even beginning to learn about the brain’s role in religion and in morality. The distinctive features of our human species are being traced to small brain areas.

We do need to remain calm in the often giddy excitement of probing the human brain. Although methods such as functional magnetic resonance imaging and electrophysiology are widely available to study the human nervous system, modern neuroscience is in reality more akin to physics in 1900, before Planck, Einstein, and the field’s other revolutionaries. New tools are powerful, but we lack the theoretical formulations needed to make the most of these new technologies. Indeed, the key questions about how a 1300-gram organ guides human behavior are not even properly articulated. We need a fusion of novel theories and questions with rigorous experimentation if the spectacular progress in physics is to occur in the biology of the mind.

Law is the polar opposite of neuroscience in many ways. Law usually requires dichotomies – guilty or not, insane or not, liable or not – whereas scientists discover that physical and mental factors vary along multiple intersecting dimensions. Courts normally reach decisions about individuals, whereas much of science is done with statistics on groups. Laws change much more slowly than science, and lawyers generally value tradition over innovation. Our system of law embodies centuries of thought and beliefs about the human mind and human behavior, largely based on casual observation, unexamined assumptions, and untested reasoning. Much of the law accepts assumptions from culture and commonsense without controlled experiments.

This common understanding of our lives will be transformed in many ways by the emergence of neuroscience. This transformation will inevitably affect the legal system, but it is not inevitable that the legal system will use that new knowledge well. Understanding what neuroscience can and cannot do for the legal system will gain increasing importance over the coming decades.

Now is the time to start integrating this new neuroscientific knowledge within the context of law. Many basic questions that form the crux of the legal system, both criminal and civil, are ripe for experimental investigation. How does one come to be a “law-breaker”? Is there a biological basis for criminality or for psychopathy? What is the neural basis of self-destructive behaviors, such as drug abuse and gambling, that overload the justice system? Do early socio-economic deprivations alter brain development, and how might this influence the likelihood of problems with the law as an adult? Why does one person respond to stress with reason and another with violence? Why do some wealthy professionals risk prison in order to boost their incomes by a small percentage? How is the fabric of morality instantiated in the brain, and how do moral judgments affect the law? Can the social neuroscience of group or interpersonal interactions provide insight into the jury system? Can neuroscience be used to determine whether a person is lying or telling the truth? Biased or neutral? All of these issues are amenable to subtle techniques that are available now.

As neuroscientists investigate scientific issues relevant to the law, legal experts need to explore ways in which neuroscience can be integrated into the legal system. Does the law of criminal responsibility need to be reformed in light of neuroscience? When, if ever, should brain scans be allowed as evidence in trials or parole hearings? How should prison officials treat convicted criminals with brain abnormalities?

Appropriate answers to these questions could bring many benefits. However, the potential benefits of proper uses of neuroscience in law could easily be outweighed by the harm caused by its misuse. The commercial introduction of fMRI or EEG-based lie detection, for example, without rigorous proof of accuracy could lead to disaster for the field – as well as for those individuals harmed as a consequence of flawed tests. Expertise in fields related to law will be crucial to assessing both how neuroscience is likely to be used in the legal system and how it should be used in that system.

Neither of these tasks – neuroscience research into issues relevant to the legal system and legal research into the uses of neuroscience in law – can be accomplished well without the other. The neuroscientists need law professors and social scientists to help them understand exactly which issues are going to be relevant to the legal system and in which ways. On the other hand, legal experts without the guidance of neuroscientists risk being diverted into ultimately irrelevant scenarios from science fiction. To provide useful answers, each discipline needs to work with the other to understand these interactions. That kind of deep interdisciplinary collaboration is a challenge to create and sustain, but it is the only way to deal properly with law and neuroscience.

The Theme of Criminal Responsibility

Because so many issues fall within law and neuroscience, our Initiative needs to focus initially on a subset of this large field. This focus will provide structure to the Initiative’s various programs and will enable us to achieve substantive results more quickly. After careful deliberation, we determined that the best focus for our Initiative at its beginning is criminal responsibility.

One reason is that the law of criminal responsibility is better defined than the law in other areas that we considered, such as neural enhancement, civil damages, intellectual property, and lie detection. Another reason is that criminal law has immense practical impact on criminals, victims, and the rest of society. Moreover, new technologies in neuroscience, such as mobile brain scanners that can be brought into prisons, have opened up exciting possibilities for research into criminal responsibility. Furthermore, criminal responsibility can be used as a vehicle to raise many related issues, such as civil responsibility, involuntary civil commitment, quasi-criminal commitment, competence, and personhood. Finally, criminal responsibility captures public attention and raises broad questions about human nature.

The relevance of neuroscience to responsibility can be illustrated by a famous example. On August 2, 1966, Charles Whitman climbed a tower at the University of Texas at Austin. Within 90 minutes, he had killed 14 people and wounded 38 more with a high-powered rifle. Then he shot himself. He had already killed his mother and wife with a huge hunting knife. Why? His note chillingly reported, “I cannot rationally pinpoint any specific reason for doing this.” The only explanation was given when post-mortem autopsy revealed a tumor beneath the thalamus compressing the amygdala.

Forty years ago there was no way to reveal Whitman’s tumor without surgery. Today we can view brain abnormalities using non-invasive imaging methods. We also have better information about the effects of tumors and other neural problems. These developments make life easier for many people with brain disorders, but harder for courts. Even if Whitman hadn’t killed himself and had been tried for his crimes, no evidence would have revealed his tumor during his trial, so his court would not have had to consider how his tumor affected his culpability. Today, in contrast, if a brain scan indicated a similar tumor in a murderer, then courts would have to decide whether the tumor diminished the defendant’s responsibility and whether his punishment should be reduced accordingly.

This decision would not be easy. Neuroscience has revealed that a tumor or abnormality can have very different effects depending on the exact location in the brain — and on individual brain differences. Recent research has shown that the amygdala, which is only about two centimeters long, is subdivided into several regions with very different functions. The frontal lobes are much larger and have many more functional areas. A centimeter one way or the other radically changes the behavioral effects of a brain condition. Further complications arise from differences among individual brains, which are only beginning to be studied systematically. A tumor or lesion of the same size in the same location but in two different brains can affect those individuals in different ways. Such differences make it hard to apply neuroscientific studies of groups to any particular defendant in a trial.

The legal issues are just as complex. Some commentators suggest that Whitman’s brain made him do it, and he had no control, so it would be unjust to hold him responsible. Others retort that brains do not perform actions, people do, and that the current legal standards for responsibility refer not to brain states but, instead, to mental states and capacities, so neural scans cannot be directly relevant to the legal issues. Both sides agree that the legal issues need to be clarified in light of a realistic understanding of what neuroscience can and cannot accomplish.

Tumors are not the only neural conditions that might affect criminal culpability. In Atkins v. Virginia (2002), the United States Supreme Court held that it is unconstitutional to execute mentally retarded defendants, because they cannot have the highest level of responsibility. In Roper v. Simmons (2005), the Supreme Court added that defendants also could not be executed for crimes committed before the age of 18. Several briefs in Roper v. Simmons explicitly cited the latest neuroscientific studies as evidence that adolescents’ brains are not fully developed in specific ways, especially in their frontal lobes. This lack of development was said to affect adolescents’ mental abilities, including their self-control and, hence, their responsibility for their actions. Opponents have criticized these neuroscientific arguments, but, rightly or wrongly, many observers still think that neuroscience provides the best reasons not to impose the death penalty for crimes by adolescents.

More generally, neuroscience raises fundamental challenges for criminal law as a whole. According to some commentators (Greene and Cohen 2006), our practice of punishment assumes a kind of free will that is refuted by psychological and brain sciences. Furthermore, most legal systems prescribe greater punishment when harms are intended (as in murder) than when they are not (as in involuntary manslaughter), and yet some experiments have been interpreted so as to suggest that conscious intentions do not affect actions at all or, at least, as much as we think, because our brains start to produce our actions before any intention becomes conscious. (Libet 2004, Wegner 2002) The very notion of intention is also problematic insofar as it requires courts to decide whether a defendant did or did not intend a harm, whereas scientists have long recognized a wider variety of mental states that cause acts, or increase the probabilities of those acts, only as parts of larger sets of circumstances. (Sapolsky 2006) These apparent conflicts between science and law suggest that our criminal law might need to be radically reconceptualized. Defenders of traditional criminal law find this skepticism overblown, but radical proposals based on neuroscience are becoming so widespread, even in the popular imagination, that they cannot be ignored.