Neuroscience, Freewill, and The Criminal Justice System: An In-depth Analysis.

Abstract

This research paper delves into the intricate relationship between neuroscience, the concept of free will, and their profound implications for the criminal justice system. Free will is the idea that humans can think and act independently ^[1]. The scientific studies have given us new evidence into the nature and workings of human behaviour, revealing that our behaviour is influenced by a variety of factors ranging from the brain’s chemistry to environmental conditions. This paper critically examines the scientific evidence, including neuroscientific studies, genetics, brain injuries, and hormonal influences, shedding light on the complex determinants of human actions. In this research paper, we will  examine the question of free will, then explore the findings from the field of behavioural sciences, and finally discuss the challenges and opportunities that these findings pose for the criminal justice system and call for a reevaluation of the criminal justice system’s foundational principles, encouraging the incorporation of the latest scientific discoveries to ensure a more just and nuanced approach to addressing criminal behavior and responsibility.

Keywords: Neuroscience, Human Behavior, Free Will, Responsibility, Determinism.

Introduction

“Man can do what he wills, but he cannot will what he wills,” said Arthur Schopenhauer. Free will is a long-standing philosophical issue that explores whether humans can act independently or are determined by factors such as genes, environment, or divine will. Different positions exist such as the hard determinism which denies free will, while in soft determinism (compatibilism), it allows some freedom within causal limits. Libertarianism opposes determinism, affirming free will. The libertarianism is the prominent viewpoint in the criminal justice system forming the basis for the belief that individuals bear moral and legal responsibility for their actions which in most cases are deemed to be independent without further enquiry. However, recent advances in the field of behavioural sciences have challenged this standpoint of free will by showing that human behaviour is influenced by a multitude of factors most of the time, such as genetics, hormones, brain activity, social norms, and environmental cues ^[2]. These studies posit that our actions are not produced by an independent agency but by a complex interplay between biological systems and external stimuli. Some prominent scientists even argue that “willful agency” is merely an illusion, attributing all behaviour to processes and natural laws ^[3]. This proposes recommendations for the criminal justice system to adapt to these developments effectively through implementing laws that acknowledge these findings, adjusting procedures accordingly, and developing more robust criteria for sentencing. The paper is organised as follows: The first section provides a brief overview of the concept of free will. The Second Section reviews the evidence from the behavioural sciences that suggests that human behaviour is more determined than we think and discusses the main arguments against free will. The third section examines the implications of these findings for the criminal justice system, focusing on the issues of culpability, responsibility, and sentencing. The fourth section proposes some recommendations for the criminal justice system to adapt to these developments effectively by implementing laws that acknowledge the role of deterministic factors in human behaviour, adjusting procedures to account for individual differences and circumstances, and developing more robust criteria for sentencing that consider both retribution and rehabilitation. The paper concludes with a summary of the main points and suggestions for future research or policy changes.

 Research Methodology.

The research methodology for this paper involves gathering primary and secondary data and conducting systematic analyses of behavioural science and neuroscientific research studies relevant to criminal behaviour. It aims to establish a strong base by assessing the case studies on topics such as genetics, brain lesions, hormones, and traumatic brain injuries.

Review of literature

In this research paper, we will review the  existing literature, encompassing the challenges posed by various research studies on independent agency of an individual. For instance, studies in neuroscience—like the Libets experiments—have indicated that unconscious neural processes occur before conscious decisions are made. This suggests that there may be limitations on our will. Genetic investigations, including adoption studies, have also shed light on the basis for criminal behaviour, raising questions about individual autonomy. Real-life examples such as Phineas Gage and Charles Whitman demonstrate the impact of brain injuries on behaviour. Additionally, hormonal factors like stress hormones and testosterone can influence decision-making processes.

To summarise, this review of existing literature emphasises the complexity of behavior. It implies that multiple factors shape our sense of free will. The criminal justice system faces the challenge of reconciling notions of responsibility with this evolving understanding. To adapt effectively, the system must take into account genetics, brain function, hormonal influences, and other factors when assessing and sentencing individuals. This approach aims to achieve a nuanced form of justice.

Exploring Free will via Neuroscientific and biological studies.

The concept of free will challenges us to think about how much control we really have over our actions. It raises questions about whether we have complete autonomy, whether our behaviour is shaped by forces outside our control, or somewhere in between ³. Most of us would probably agree that we do not have absolute control, and nearly everyone would believe that the answer is somewhere in between ³. This view implies that we have a core self from which emanates behavioural intent, that generates independent choices, and has the ability to act freely, but it is limited or restricted by the constraints imposed by our biology, and these constraints on free will have the power to influence our decision-making and actions to a significant extent. The thing we need to consider is that, even though we have a degree of volition, the body through which the self operates is susceptible to weakness and malfunction, and this vulnerability can erode our capacity to act freely.

Bounded Free will

Let’s explore the concept of bounded free will in the context of the famous assassination attempt on a British prime minister ^[4]. In 1842, a man named Daniel M’Naghten attempted to kill then British P.M. Robert Peel, and the reason behind this was quite sad, as M’Naughten was not in his right mind as he had some form of schizophrenia. The day after the incident, he claimed that he was having episodes of powerful figures persecuting him, which shattered his rational thinking. This case led to the establishment of the M’Naghten rule, which states that if, at the time of the crime, a person is so mentally impaired that they cannot distinguish right from wrong due to a “disease of the mind,” they may not be held criminally responsible ^[5]. This case demonstrates the idea that people might not have full control over their actions in certain circumstances; that’s something we need to consider in the criminal justice system. Further in the research paper, we will examine the significant findings from various behavioural studies influencing behaviour and thus causing the loss of agency.

The Readiness Potential – What does Neuroscience say about Free Will?

In the 1980s, debates with regards to free will were first launched in the community of neuroscience following the results of Libet’s experiments. In that experiment, the research subjects were linked to an EEG machine, which tracks brain activity, and this experiment led to the finding that the neural activity began 500 milliseconds before the reported time of conscious sense of moment ⁶. The question with concern to the time lag was interpreted by Professor Libet as the unconscious neural activity preceding the subject’s awareness of an intention to act, and this unconscious neural activity was named readiness potential ⁶. Naturally, this interpretation generated speculation and controversy as to the meaning behind the delayed time period of 500 milliseconds, and this experiment was subjected to various criticisms^[6]. Nevertheless, this experiment led to a breakthrough of unconscious neural activity, which has led us to believe that we have reached an experimental stage of proving the nonexistence of free will and providing a deterministic view of human decision-making.

Genetics and Criminal Behavior

Genes are the basic unit of heredity that carry the developmental codes for the functioning of living organisms, and these genes can have a significant influence on various aspects of human behaviour like personality and intelligence ⁷. Genetic research on crime can be seen in twin studies, adoption studies, and molecular genetic studies ⁷. These studies help identify specific genes that are associated with crime ^[7].

Twin Studies

In twin studies, the main aspect is finding the similarity in behaviour between twins and comparing it with control groups ⁸. Twin studies have consistently found that identical twins have higher concordance rates for criminal behaviour than fraternal twins and others, especially in property crimes such as vandalism and theft ^[8]. The heritability estimates of criminal behaviour from the twin studies range from 40% to 70%, depending on the sample, the measure, and the type of crime ^[9].

Adoption Studies.

In 1972, a scientist named Crowe conducted a study in Iowa with 52 adoptees whose biological mothers were engaged in criminal activity ¹⁰. He found in the research that 24% of the adoptees had been convicted of a crime, and in the case of non-adopted individuals, it was merely 4.5% ¹⁰. Which seems to suggest parental genetic influences on criminal behaviour. He also found that the adoptees were more likely to commit similar crimes, such as property crimes or violent crimes ¹⁰. Suggesting that inherited traits have a strong influence when it comes to criminal behaviour and the specificity of the crime^[10].

In 1984, another study was conducted in Denmark by Sarnoff A. Mednick, William F. Gabrielli Jr., and Barry Hutchings. With 14,427 subjects whose biological parents had criminal records in the past, they found that 13.5% of the adoptees had been convicted of a crime, compared to 8.4% of the general population.They also found that the adoptee’s risk of criminality increased if both their biological and adoptive parents had criminal records, suggesting an interaction between genetic and environmental factors ^[11][12].

Molecular Genetics.

Molecular genetics learns about the specific genes that influence behavioural outcomes, and in the realm of criminal behaviour, it can provide insights on the specific genes that influence criminal behaviour and, in its relevance, insights on impulsivity, violence, personality disorders, etc¹³. Some recent studies have identified genes that have a significant influence on criminality, such as the MAOA gene and the CDH13 gene ¹³ ¹⁴ ¹⁵. MAOA main role is to produce an enzyme that is involved in the breakdown of neurotransmitters like dopamine, serotonin, and noradrenaline. As these neurotransmitters are important for regulating mood, emotion, and impulse control in the brain ¹³, some variants of the MAOA gene can affect those neurotransmitters and make people more sensitive to stress and more prone to antisocial behavior. This effect is especially strong when combined with environmental factors like childhood trauma or substance abuse. The CDH13 gene is another such gene that is related to criminal behavior. The CDH13 gene codes for the protein that helps neurons stick together in the brain; this gene is said to increase the proclivity for violent and irritable behavior^[13]. According to one study, people who had both of these MAOA gene and CDH13 gene variants were 13 times more likely to have an inclination towards criminal behavior. The study also estimated that 5–10% of all violent crime in Finland could be attributed to these genotypes^[14][15]. In conclusion, various types of genetic research studies, such as twin studies, adoption studies, and molecular genetic studies, show that inherited traits possess a significant influence on the behaviour of a person, including those related to criminal behaviour, and have the ability to affect one’s free will. Thus, the criminal justice system must emphasise the need for comprehensive evaluations that consider the genetic basis of crime.

Brain Lesions, Tumors, Injuries and Criminal behavior.

The brain is susceptible to various forms of damage, such as lesions, tumours, and traumatic injuries. These kinds of damage can have a toll on the way our brain functions and can also lead to changes in behavior. Let’s examine some of the cases where brain damage has led to criminality and violence.

Brain Lesion Case study

The most famous case involving brain lesions is that of Phineas Gage, a railroad worker who survived a horrific bomb blast in 1848¹⁶. He was then working on a new railway line and was packing explosives into a hole with a rod, and then suddenly, one explosive burst, sending the rod, which he held, through his skull. The rod entered his left side of the face, passed through his left eye, and came out through the top of his head, destroying much of his left frontal lobe¹⁶. Gage miraculously survived this incident, but his behaviour was said to have changed a lot as he became more impulsive and rude after the incident took place^[16].This case raises a serious question for the criminal justice system: how is it going to incorporate studies such as these into its standards and practices? How can it identify and assess offenders who have suffered from brain injury? , and what procedures can the courts implement to address this concern?

Brain Tumor Case study.

One of the most tragic examples of how brain tumours can lead to a loss of free will is the Charles Whitman case. On the first of August 1966, he went on a murderous shooting rampage, killing 16 people and wounding 31 others¹⁷. The sad thing was that he killed his own mother and wife the night before. He got killed by police authorities after an hour of rampage ¹⁷, after which, in his medical examination, it was found that he had a glioblastoma, a particular kind of tumour that grows aggressively and is also capable of infecting nearby brain tissue¹⁷. This case gives us an idea of how certain deformities can completely take away our control of our body and mind and lead us to do things that we can’t even imagine in our wildest nightmares. Whitman’s case raises many questions related to the influence of biology on human behavior^[17], One of the important questions in this concern that needs to be considered by the criminal justice system is, How can we evaluate the responsibility and accountability of those who commit crimes because of the circumstances that completely removed their free agency?.

Traumatic Brain Injury Case Study.

A study on traumatic Brain Injury was conducted by Brower and Price (2001), in which 15 subjects became violent after they had a traumatic brain injury. Most of subjects in this study had a damage to the frontal lobe, which can seriously effect the executive functions, such as planning, reasoning, and problem-solving. The researchers suggested that the TBI can remove our ability to control our impulses and to think about the consequences of our actions^[18][19]. Thus limiting or removing our freewill depending on severity of the brain injury.

Hormones and Criminal Behavior.

The hormones play a very important role in regulating our body and brain, and they can also influence our behaviour. In the context of criminal behaviour, some of the important hormones are sex and stress hormones ²⁰. Studies have shown that stress hormones such as cortisol and adrenaline can affect people by impairing their rational thinking and memory and can increase the level of anxiety. These hormones mainly take effect during fight or flight situations ²⁰. Testosterone, a male sex hormone, is said to cause aggression and antisocial behaviour when it is at higher levels^[20]. The hormone that is highly found in females, Estrogen, has been linked to higher levels of empathy and greater sensitivity to social cues. These hormones have a necessary influence over behavioural outcomes, thus seeking relevance in the criminal system.

Thus, with respect to the above information, the criminal justice system should take into account the hormonal levels of the offenders, as circumstances exist wherein one may get blinded by the influence of hormones to a certain level, which can have a significant impact on their free will during the circumstances of the offense. It can implement approaches such as measuring hormone levels in blood, saliva, or urine samples from the offenders and comparing them with the behavioural measures of the control group. If the offenders have a high level of hormones that can lead them to criminal behavior, then in this case, necessary procedures for manipulating the hormone levels experimentally should be considered. However, measuring and manipulating hormone levels in offenders is not a straightforward task. There are many ethical, practical, and legal challenges involved in such an approach. For example, how can we ensure that the offenders consent to the hormonal testing and treatment?  How can we account for the individual differences and variations in hormonal responses? How can we avoid potential side effects or adverse reactions to the hormonal interventions? How can we evaluate the effectiveness and validity of the hormonal approach? These are some of the questions that need to be addressed before implementing such an approach in the criminal justice system.

From Brain to the Bar – Redefining the theories of Culpability, Responsibility and Sentencing.

The concept of culpability mainly concerns the degree of blameworthiness of the individual, and it also refers to the principle of “mens rea,” which represents the mental state or intention of the accused at the time of committing a crime. that must be proven for the accused to be held criminally liable. One must take notice that culpability is a graded concept, and depending on the moral blameworthiness, whether it be high, partial, or nil, the appropriate sentencing is given. With regard to the concept of responsibility to the persons effected by the disorders and weaknesses that bound one’s free will, the legal defence of diminished responsibility can be used to make a case, as the accused wasn’t in his complete agency, and depending on the circumstances of the case, diminished responsibility serves as a legal doctrine that acknowledges that not all individuals are in full control of their actions due to factors such as mental illness, neurological conditions, or other substantial impairments of their mental faculties. It recognizes that these factors can significantly reduce an individual’s capacity to form the requisite mens rea or guilty intent necessary for criminal liability. the court must refer to this idea and can critically examine the level of agency the person was equipped with and give sentences accordingly. The courts should also consider the critical role played by behavioural scientists such as psychiatrists, psychologists, etc., in the assessment of the capacity of the accused. Through evaluations and expert testimony, these professionals provide crucial insights to help courts determine culpability and recommend appropriate actions, ensuring a balanced  approach to cases involving issues that limits ones free will. The courts must also observe the ongoing scientific findings and clearly define rules on this basis for maximal justice; one example presented by the author is an annual review procedure of the laws with respect to the scientific findings and studies and also observing new philosophical concepts in their alignment, which the author deems important, in order to stay scientifically relevant in imparting justice rather than using vague old concepts. The sentencing in the light of the deterministic evidence on the loss of free agency poses a challenge to the criminal justice system as to its goal. The complexity must be adequately met by flexible procedures that delve into the unique aspects of the case. The author observes that sentencing must take a hybrid view, combining elements from both consequentialist and compatibilist views. Where it acknowledges that both outcomes and motives matter, and it would thus balance the interests of offenders, victims, society, and justice in determining the type and duration of punishment depending on the specificity of the case concerned. Thus sentencing should be a dynamic process that reflects our constantly changing  understanding of human behavior, responsibility, and the pursuit of justice. This adaptive approach ensures that the criminal justice system remains both relevant and equitable in the changing world.

Suggestions and Conclusion.

The current criminal justice system should base its philosophical foundation on the latest scientific discoveries that shed light on factors that can affect the free agency of an individual. The person who does not have full control over his actions should not be subjected to the outcome as a criminal; this defeats the point of justice. The courts should take account of the different levels of agency of individuals in order to give maximal justice. The courts should also adopt flexible methods to examine the specific facts presented in each case. The experts from behavioural sciences, such as psychiatry and psychology, must be given relevance to participate in the criminal proceedings in order to determine the capacity of the individuals. Now, with regards to sentencing, the courts must follow a hybrid approach, combining both the elements of consequentialist and compatibilist views. This way, we can balance the interests of offenders, victims, society, and the principles of justice when deciding the appropriate sentences for the concerned cases. This adaptive approach ensures that the criminal justice system remains fair and applicable in the changing world.

S. Chetan Siri Sai,

Dr. B.R. Ambedkar Law College, Osmania University, Hyderabad, Telangana.

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^[1] Free will – Psychology Today https://www.psychologytoday.com/us/basics/free-will

^{[2] Robert Sapolsky, BEHAVE: THE BIOLOGY OF HUMANS AT OUR BEST AND WORST 50 (Penguin Books 2017).}

^{[3] Klein, J. Neurolaw: Criminal Justice in a World Without Free Will. Brown Political Review. (2018, January 29). https://brownpoliticalreview.org/2018/01/neurolaw-criminal-justice-world-without-free-will/}

^[4]  “M’Naghten’s Case.” Casebriefs, 2021, [https://www.casebriefs.com/blog/law/criminal-law/criminal-law-keyed-to-kadish/exculpation/mnaghtens-case/amp/].

^[5] “The M’Naghten Rule.” FindLaw, 2021, https://www.findlaw.com/criminal/criminal-procedure/the-m-naghten-rule.html.

^[6] Libet’s experiments. Information Philosopher. (n.d.), from 3 https://www.informationphilosopher.com/freedom/libet_experiments.html

^[7] Carrabine, Criminology: A sociological introduction. In E. McLaughlin & T. Newburn (Eds.), The SAGE handbook of criminological theory (pp. 3-26). E. . SAGE Publications. (2010).

^[8] Wertz, J., et al. Genetics and Crime: Integrating New Genomic Discoveries Into Psychological Research About Antisocial Behavior. Psychological Science, 29, 791–803. (2018).

^[9] Mednick, S., Moffitt, T., & Stack, S. Evidence for the Role of Genetics. In The Causes of Crime: New Biological Approaches. Cambridge: Cambridge University Press. (1987).

^[10] Joseph, J. Is Crime in the Genes? A Critical Review of Twin and Adoption Studies of Criminality and Antisocial Behavior. The Journal of Mind and Behavior, 22(2), 179–218. (2001). http://www.jstor.org/stable/43853952

^[11] .Mednick SA, Gabrielli WF Jr, Hutchings B. Genetic Influences in Criminal Convictions: Evidence from an Adoption Cohort. (1984). Science, 224(4651), 891-894. doi: 10.1126/science.6719119. PMID: 6719119.

^[12] Mednick, S.A., Gabrielli, W.F., Hutchings, B. Genetic Influences in Criminal Behavior:Evidence from an Adoption Cohort. In: Van Dusen, K.T., Mednick, S.A. (eds) Prospective Studies of Crime and Delinquency. Longitudinal Research in the Behavioral, Social and Medical Sciences, vol 2. Springer, Dordrecht. (1983). https://doi.org/10.1007/978-94-009-6672-7_4

^[13] Breen, G., Li, Q., Roth, B. L., O’Donnell, P., Didriksen, M., Dolmetsch, R., … & Sklar, P. Translating genome-wide association findings into new therapeutics for psychiatry. Nature Medicine, 22 (11), 1195–1206 (2016). https://www.nature.com/articles/mp2014130

^[14] Tehrani, J.A., & Mednick, S.A. (n.d.). Crime Causation. In Law Library – American Law and Legal Information.  https://law.jrank.org/pages/795/Crime-Causation

^[15] Paul, S. The Criminal Behavior of Genes. In Science Repository. (November 19, 2020). https://www.sciencerepository.org/the-criminal-behavior-of-genes

^[16] Jarrett, C. “Psychology’s 10 Greatest Case Studies – Digested.” Big Think.  (August 30, 2018). https://bigthink.com/mind-brain/psychologys-10-greatest-case-studies-nil-digested/ .

^[17] Johnson, Micah.  “How Responsible Are Killers with Brain Damage?” Scientific American. (2018, January 30). https://www.scientificamerican.com/article/how-responsible-are-killers-with-brain-damage/.

^[18]  Perry, Philip. “New Study Links Brain Injuries to ‘Acquired Sociopathy’.” Big Think. (2017, December 29). https://bigthink.com/surprising-science/these-types-of-head-injuries-could-increase-your-risk-of-committing-a-crime/

^[19] Brower MC, Price BH. Neuropsychiatry of Frontal Lobe Dysfunction in Violent and Criminal Behavior: A Critical Review. (2001, December). J Neurol Neurosurg Psychiatry, 71(6), 720-726. doi: 10.1136/jnnp.71.6.720. PMID: 11723190; PMCID: PMC1737651.

^[20] Ellis, L. Hormones, the Brain, and Criminality. In G. Bruinsma & D. Weisburd (Eds.), Encyclopedia of Criminology and Criminal Justice. Springer, New York, NY. (2014). https://doi.org/10.1007/978-1-4614-5690-2_59