The biology of criminal behaviour: Whether or not it’s all in the genes

Introduction

A significant body of literature exists on biological causes for antisocial and criminal behaviour. This paper provides a selective overview of three biological factors: psychophysiology (with a focus on reduced heart rate and skin conductance), brain mechanisms (with a focus on structural and functional abnormalities of the prefrontal cortex, amygdala, and striatum), and genetics (with an emphasis on gene-environment and gene-gene interactions).

Understanding the role of genetics in antisocial and criminal behaviour has the potential to improve the explanatory power of current studies and ideas, as well as to guide policy and treatment alternatives.[1]

There is no single “cause” of crime. crime is a complex phenomenon that differs in many cultures and over time. Activities that are legal in one country may not be legal in other countries. practice that once was not criminalized can be criminalized (and then decriminalized again) as cultures change over time.

As a result, there is no entire response to the subject, “what is crime?” and therefore, there is no universal answer to “what causes offense?” Different forms of crime have their own distinct causes.

However, the biology hypothesis of crime posits that our genetic makeup influences criminality in various ways. We will go through what this theory comprises as well as other related vocabulary. In addition, we shall look at its history before moving on to recent crime theories.

The determinants covered in this article have a complex role in criminal conduct, and the processes by which this occurs aren’t always evident. This paper provides an overview of some of the important criminological hypotheses that attempt to unravel the roots of the problem; it is far from exhaustive.

Each of the ideas discussed has its own set of strengths and flaws, that must be applicable to some types of crime but not others There is no ‘correct’ or ‘incorrect’ theory therefore.

The hypotheses discussed can be divided into two categories:

• Biological hypotheses
• Theories of sociology

History and overview

No one is born a criminal since crimes are socially defined. A link must be established between some other common factor such as hostility, impatience, danger, and so on. According to biological theories of crime, the extent to which people commit crimes is determined by their fundamental character which is genetics.

Biological traits related with criminality, according to biological theories of crime, could include inheritance, psychology, or physical composition. Although many biology-based theories of crime take into account the impact of situational and surrounding elements (what criminologists refer to as biosocial models), biological criminal behaviour theories differ from sociological perspectives in their emphasis on internal aspects. Biological explanations of crime emerged concurrently with their sociocultural versions.

In the nineteenth century, research scholars and criminal behaviour experts established forensic biology as a science in itself in Italy. Under the influence of both pseudo-science (now-defunct research of the aspects of the skull as suggestive of mental capabilities and personality characteristics) and Darwin’s theory of evolution, they introduced the concepts of the “born criminal.”

Criminologists frequently contrast biological theories of crime with sociological ideas. These crime statisticians compiled and analyzed statistical data to determine the quantity and distribution of crimes, establishing links between age, race, social origin, and crime.

These findings supported the concept that crime was caused by environmental, social, and biological causes. other studies that claimed criminality could still be explained only by genetic tendency. Physiological anomalies that lead to crime can occur in the brain or skull, as well as in the body’s structure.

Most criminal scientists have rejected the notion that criminality can only be characterized by biological anomalies in the criminal, instead favouring techniques that mix biology and sociology.

According to research into biological explanations of crime, certain (lower) social groups and races are genetically predisposed to physical and mental diseases, rendering them more inclined to commit crimes. Scholars believed that criminals may be distinguished from the normal community by their appearance These individuals have atavistic, or primal, characteristics.

Thieves had exaggerated facial expressions, manual dexterity, and small, wandering eyes; murderers had cold, glassy stares, bloodshot eyes, and hawk-like noses; sex offenders had thick lips and protruding ears; and female criminals were shorter, wrinklier, had darker hair, and committed smaller crimes than normal women.[2]

Criminals were at a more primitive evolutionary stage than non-offenders, making them unwilling adapt into modern society and thus more likely to commit crime. This was accompanied by the assumption that misconduct was hereditary.

People who commit crimes fall into two categories: life-course-persistent offenders, whose antisocial, criminal behaviour begins in childhood and worsens through time, and adolescent years offenders, whose antisocial behaviour begins in adolescence but stops in early adulthood.

While life-course-persistent offenders are rare but abnormal, adolescent-limited offenders are quite numerous, momentary, and close to normal. As one of the most commonly accepted modern theories of crime, these theories had significant ramifications for criminal policy.

Advances in genetic theories of crime focus on how distinct parts of the brain are involved for perceptions, sentiments, and behaviours, and how malfunctioning in these regions can lead to criminal behaviour.

In current biological research of crime, criminologists and neuroscientists have focused on numerous areas of the brain. The cerebral cortex is the brain’s outer layer and is separated among left and right regions. There are four lobe in each hemisphere.

In their biological theories of crime, criminologists and company that does research in various areas like social science or criminology have emphasized on the frontal lobe because the region is engaged in abstract reasoning, thinking, goal development, maintaining concentration and focus, self-monitoring, and behavioural inhibition.

Researchers studied 41 violent killers and discovered lower activity in the prefrontal brain and frontal lobe of these offenders when compared to control non-criminals. Individuals suffering from Antisocial Personality Disorder (psychopathy) have a decreased emotional reaction and a lack of empathy for others.

Many criminals have displayed these indications. Neuroscientists also investigate how molecules in the brain called neurotransmitters influence thought, emotion, and behaviour. Excessive dopamine levels, for example, have been linked to aggressive and criminal conduct in some studies, and antipsychotic medicines that diminish dopamine may potentially be used to lessen aggression.

Similarly, scientists have discovered that high levels of norepinephrine can contribute to violent conduct, while low levels can lead to antisocial behaviour. These findings demonstrate that both elevated / low norepinephrine levels can cause behavioural issues. Serotonin, an inhibitory neurotransmitter used across the brain, including the limbic system and frontal cortex, is another neurotransmitter of relevance to biological theories of crime.

Researchers discovered that low serotonin levels are associated with criminal behaviour and that the neurotransmitter regulates impulsivity.[3]

Biological theories of crime

Biological theories of crime thus mix crime with biology. These ideas attempt to explain why people commit crimes by examining their physical, genetic, and neurological characteristics. All biological theories of crime can be classified into three types based on the characteristics they investigate:

1. Methods for identifying offenders based on their physical appearance
2. Theories that attribute criminal behaviour to hereditary factors
3. Ideas that attempt to explain criminal inclinations by examining distinctive characteristics in the brain and body

The earliest beliefs of this sort focused primarily on the biological aspect, claiming that criminals are born rather than formed, whereas some current offshoots also consider external variables. Unlike biological ideas, classical theories assumed that committing an offense is solely a choice with no environmental circumstances or specific biological features.

Both strategies have been shown to be excessively severe, but it is uncommon for an older hypothesis – i.e., ancient philosophy – to be more in accord with empirical facts than a newer one. A current biological explanation of crime focuses on neurological and genetic components in an attempt to explain a criminal’s mental state. There are other biological theories that combine other domains, such as biosocial perspectives.

Genetics-focused theories

Although research suggests that some hereditary features may relate to anti-social or criminal behaviour, the role of genetics in human behaviour is still being debated. There is some research that supports a genetic link between persistent wrongdoing and, in particular, felony crime.

Perhaps of evaluating physical aspects of the body, modern approaches concentrate on: Biochemical problems (e.g., those associated with poor diet or hormonal fluctuation) Neurophysiological disorders (for example, learning impairments induced by brain injury) Genetic ancestry and/or anomaly

The intelligence in these efforts to pinpoint the underlying causes of crime within the person imply that there are discernible distinctions between offenders and non-offenders. In other words, the criminal is ‘other’: distinct or odd in some way from everyone else.

On contrary, there is scant evidence linking a genetic connection to violent crime. There is also a small but growing amount of research regarding the risk and preventive variables associated with specific genes. A genetic that confers a low rate of the enzyme monoamine oxidase, for example, may increase susceptibility to violent or anti-social behavior. This relationship, however, emerges only when a person with that gene was abused as a youngster.

Criminologists, like early biological theories of crime, have employed parental, adoption, and twin studies to estimate the extent to which particular qualities are heritable. In this research, if an individual’s behaviour is more similar to that of their biological family than to that of their adoptive relatives, it implies that a trait is influenced more by genetics than by environment.

According to the study’s findings, 13.5% of adoptees whose adopted or birth parents had never been found guilty of a crime were prosecuted. Only 14.7% of those who had only their adoptive families convicted became prisoners.

These findings imply that the qualities that lead to delinquency are heritable, but individuals raised in an atmosphere where they are subjected to criminal conduct are more likely to participate in it themselves. These findings have been corroborated by more recent crime adoption studies.

The researchers discovered that additive genetic factors account for approximately 32% of the variation in antisocial conduct, 9% for nonadditive genetic effects, 16% for environmental impacts shared by the twins, and 43% for unique environmental factors not shared by the twins. Researchers determined that genetic influence accounted for around 50% of the population’s diversity in antisocial behaviour.[4]

Neurological theories of crime

Hormones are chemical substances that the body utilizes to communicate with one another. The three substances that have received the most attention in terms of research are serotonin, norepinephrine, and dopamine.

Hormonal changes and criminal activity are linked. Overall, there appears to be a substantial link between low serotonin levels and anti-social conduct, a moderate link for norepinephrine, and no influence for dopamine.

Numerous studies have discovered associations between low serotonin activity and children’s conduct problems, antisocial personality disorders, and criminality, particularly impulsive offenses.

Some types of criminal behaviour are related to dysfunction in the neurotransmitters employed by the brain. Damage to the brain’s structure and function has been linked to antisocial or abusive behaviour. This study of the anatomy and operation of the brain is known as neurobiology.

It has been proposed that certain hormonal imbalances influence the possible emergence of antisocial tendencies. Cortisol and testosterone are the hormones that regulate and have sparked the greatest speculation. Low cortisol levels, an anxiety hormone, can cause a distorted perception of stress and a lack of awareness of its effects.

Higher testosterone levels, on the contrary hand, may make someone much more susceptible to violent conduct. Finally, when their amounts inside the body were reversed, both hormones produced similar consequences. The rationale for this notion is that males appear to demonstrate more violent conduct than females

Advances in technology for observing the brain in action (for example, functional magnetic resonance imaging) have brought fresh insights into how the brain works.

There is mounting evidence that neurological impairment is a key mediating process that leads to crime. Evidence suggests that damage to the prefrontal cortex caused by head injury, birth difficulties, sickness, or an environmental toxin (such as alcohol or other drugs) is connected to antisocial behaviour.

Pre-frontal damage is thought to limit the ability to control impulsive, aggressive feelings, inviting risk-taking, rule-breaking, sentimental and hostile outbursts, and resulting in poor mental capabilities, loss of intellectual fluidity, and problem-solving skills, all of which lead to academic failure.

Risks to the developing brain emerge even before birth in the form of chemicals that can harm the unborn, most notably cigarettes, alcohol, and other drugs. Bad experiences throughout a child’s early years of life, such as chronic mistreatment, physical abuse, or neglect, can over-activate the stress response system, resulting in neurological dysfunction that predisposes a person to criminality.

However, its development is heavily influenced by a person’s parenting and early life, and it can be significantly hampered by environmental variables such as stress caused by low socioeconomic background or torture.

Biosocial theories

The biosocial hypothesis is a behavioural and social science theory that characterises personality disorders, mental diseases, and impairments as physiologically driven personality features that respond to environmental stimuli.

Biosocial criminology is an interdisciplinary subject that investigates biocultural elements to explain crime and antisocial conduct. While sociological theories have dominated contemporary criminology, biosocial criminology recognises the potential contributions of sciences such as behavioural genetics, neurobiology, and evolutionary psychology.

Some researchers have concluded that biological traits cannot be utilised as the only basis for human behaviour. As a result, a new set of hypotheses combining sociological and biological features arose. They are known as biosocial theories.

These theories consider the above-mentioned key parts of the neurobiological concept of crime, as well as social circumstances such as growing up in a disturbed family, being mistreated by peers, among others. That is why laws exist to address the problem of parental responsibility in combating neglect and abuse of children.

Biopsychosocial theories

When examining crime causation, biopsychosocial theories of criminal behaviour involve three disciplines, as the name implies:

• Biology
• Psychology
• Sociology

A case study of the famed serial killer Theodore Robert Bundy is one of the modern biological theories of crime instances examined through the lens of sociological and psychological theories of crime.

Ted Bundy was born in Burlington, Vermont on November 24, 1946. He was raised by his grandparents, who nurtured him as if they were his parents and his mother was his sister. His grandfather had violent outbursts, while his grandmother had agoraphobia and despair. As a result, his childhood was everything than ideal.

Bundy had a bright future as a law student. From the outside, he appeared to be a nice, though introverted, individual. Nonetheless, he went on to conduct nearly 30 murders between late 1973 and 1978.

All of his victims were female. His apparent motivation was retaliation after his fiancée dissolved their affair. Biological impacts are difficult to establish in this environment. Social and psychological elements appear to be taking precedence: Given Bundy’s grandfather’s aggressive inclinations, it’s possible that Bundy’s behaviour was influenced by him.

Ted’s upbringing is thought to have had a considerable impact on him, and the confusion and pain he endured surely influenced his outlook on the world and his standing in it, especially when it came to women.

When considering this serial killer, numerous diseases have been thrown around in psychiatric jargon. The three most common are narcissism, borderline, and antisocial personalities. While he most certainly had them, its reasons in Bundy are unknown.

One of the aims of criminal psychology is to identify and investigate the psychological elements that contribute to criminal behaviour. That is why additional research and studies are needed to gain a better knowledge of human behaviour and avoid bias-based convictions.

Mental health

Mental health is at the crossroads of biological (genetics and neurology) and social elements (such as post-traumatic stress disorder caused by trauma or abuse). Evidence demonstrates that both direct and indirect relationships between mental health and criminality exist.

According to the Dunedin Multidisciplinary Health and Development Study, individuals with mental problems account for a significant percentage of violence in the community in the age group committing the most violent acts.

In terms of indirect ties to criminality, maternal mental health problems are linked to unfavourable consequences for children, such as emotional and behavioural issues.

Certain psychological disorders do raise a person’s likelihood of committing a crime. According to research, persons with mental illnesses who do not receive proper treatment, are actively undergoing illusions, or have lengthy paranoia may be more vulnerable to violence.

Such people frequently exhibit symptoms of their psychiatric disorder, such as control hallucinations. Other comorbidities include drugs use disorder, unemployment, homeless, and secondary impacts of mental disorder such as memory loss, all of which increase the likelihood of initiating a violent crime.

A long-term substance use problem is the most major and significant risk factor for criminality and aggressiveness among people with mental illnesses. Patients with a serious psychological disease with a concomitant drug use disorder are four times more likely to commit a crime or act violently.

According to studies, the surge in violent crime perpetrated by those suffering from mental illnesses can be attributed solely to a background of alcohol and/or drug use.

Individuals with serious mental illnesses who fall through the cracks or are non-adherent to treatment for one reason or another are more at danger of committing heinous acts of violence.

Untreated serious mental illness is very crucial in homicide cases—the pinnacle of the criminal spectrum—and it is even more significant in mass murders of outsiders. Nonetheless, these incidents pale in comparison to mindless acts of violence carried out by criminals acting solely for criminal gain.

Many people suffering from mental illnesses confronts an uphill battle in obtaining treatment for their problems. Many people do not obtain the necessary and timely therapy.

In many places, budget overruns and reductions in financing for public health and mental health increase the likelihood that people with mental illnesses will be involved in criminal behaviour. The lack of mental health care facilities complicates matters even more.

Despite increased awareness and efforts to improve access to psychological treatment facilities, the number of mental hospital beds per capita in the United States is lower than it has been since the 1850s.

The relationship between psychiatric illness and criminality is complicated and has far-reaching societal ramifications. In-depth research and creative solutions for access and availability of mental health treatment are desperately needed.

There is currently little evidence that mental illness can predict criminal behaviour independently. On the contrary, there is considerable evidence that people with mental illnesses are significantly more likely to be victims of violent crime than perpetrators.

Other socio-biological factors

A lot of other political and social factors may influence an individual’s likelihood of criminal behaviour, but the research is insufficient to be definitive.

Low intellect, poor food, impulsivity and restlessness, hormones like testosterone and cortisol, and environmental toxins can all influence a person’s inherent proclivity for violent or antisocial behaviour.

Emerging data about the correlates of these and related characteristics is assisting in the construction of a more complete understanding of the biological basis for human behaviour. The evidence for a causal association between various biological risk factors and criminal behaviour is growing.

Limitations of modern biological theories of crime

Biological genetic studies are limited in that they cannot pinpoint which genetic variables generate behavioural differences. Many genes have the potential to impair normal development, resulting in aberrant behaviour. Scientists undertook molecular genetic experiments to determine which genes may be linked to antisocial and criminal behaviour.

Criminologists are interested in two sorts of genes: those that regulate dopamine and those that regulate serotonin. Variations in dopamine levels in the brain can cause a wide range of behaviours, and polymorphisms in the genes that govern dopamine can cause significant and violent antisocial behaviour.

There are also a number of genes that code for the generation, detection, and removal of serotonin in the brain, and studies have shown that low levels of serotonin are linked to an increase in antisocial behaviour. Because it has implications for the legal system and society as a whole, the biological approach is socially sensitive.

If offending is genetic, people should not be held accountable for their actions; nonetheless, this leaves an essential decision to be made about what to do with these hazardous offenders. According to this hypothesis, crime prevention methods could involve genetic testing of the general public, but what do we do with people who have genes that predispose them to crime?

Conclusion

Clearly, no single theory properly explains why someone would commit a crime, owing to the fact that criminal behaviour is not a fixed concept: what is illegal and what isn’t changes with the legislation, not through biological causes.

Biological theorists examine causation from a biological standpoint, seeking reasons in neurology, genetics, and physiology. However, because social and economic factors continue to be the most powerful predictors of antisocial conduct, these theories would be wise to embrace at least a portion of that explanation.

References:

[1] Website title: PubMed Central (PMC), https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6640871/ date published: 30^th January 2019,Date accessed 15^th November 2022.

[2] Website Title: Biological Theories of Crime – Simply Psychology,https://www.simplypsychology.org/biological-theoriescrime.html#:~:text=Biological%20theories%20of%20crimes%20state,%2C%20neurology%2C%20or%20physical%20constitution.

[3] Website Title: Biological Theories of Crime – Simply Psychology,https://www.simplypsychology.org/biological-theoriescrime.html#:~:text=Biological%20theories%20of%20crimes%20state,%2C%20neurology%2C%20or%20physical%20constitution

[4]  Website title: Biological Theories of Crime – Simply Psychology,https://www.simplypsychology.org/biological-theories-crime.html

This article has been authored by Riddhi Rahi, a student at UPES, Dehradun.