Title: The Heritable Component of Crime and the Genetics of Justice

Author: Mr. Faizan Anwer

Volume 1 Issue 1

January 2019

ISSN: Applied for…


We are living in a multidisciplinary era. Since the dawn of civilization, every field of study have progressed at its own pace and there have been continuous research and findings at different levels of different diversified fields. There was a time when shooting off of various sciences was an essential phenomenon for inculcating expertise and advancement within a particular area of study. Now all these branches are converging and interconnecting and forming nodes with other fields. Legal studies are no exception to this. In this article, we will try to put some light on criminology with the glasses of biology.  The phenomenon of crime integrates multiple factors including human behaviour, psychology, sociology, parenting, forensics, and more recently genetics. The genes present in our very cells may be the causal agent for criminal behaviour, but it’s not a tool to escape from the punishment of one of the most heinous crimes done by most advanced species, Homo sapiens present on the face of the earth. In the advanced modern societies, government prepare the databases of DNA fingerprints of the evil souls of the society. There have been detailed discussions on eugenics and epigenetics. One of the interesting facts is that capital punishment may be one of the methods of implementing eugenics in the core of civilization. The phrase of nature and nurture is very analogous to genetics and epigenetics in this scenario. We all are the products of genetic composition and socioenvironmental factors. Does this rob our free will or does this make us liable?


As the progressive advancement in the field of biology especially bioinstrumentation is taking place, the probability of increasing the accuracy will also increase as a result of which the admissibility of all these biology based evidence in the court will have greater chances. In family court matters, polygraph evidence has been accepted by the courts in certain cases although it has faced continuous rejection as evidence in criminal trials.

Genetic structure, neurotransmitters, hormones, central nervous system, autonomic nervous system and environmentally induced genetic factors work in synchronization to regulate and control the human behaviour and psyche. The correlation between biology and crime dates back to 1876 when an Italian physician Cesare Lombroso [1] published his view on the doctrine of evolutionary atavism and since then this correlation has been presented in different ways and in different magnitudes. The causal genes for correlation between the crime and genetics have been identified as MAOA gene and a variant of cadherin 13. Due its relevance to crime MAOA is also known as “The Warrior Gene”. MAOA (Monoamine Oxidase A) gene codes for an enzyme that helps in breaking down of various neurotransmitters including serotonin, dopamine and noradrenaline. These neurotransmitters are responsible for impulsive behaviour. The correlation between aggression and neurotransmitters has been found in both animals and humans.

The very important question to raise is that, Is behaviour voluntary or involuntary?

If the behaviour is an involuntary phenomenon then how do we do justice to criminals like murderers? It is very possible that in certain situation behaviour is voluntary and in some other situations, it may be involuntary. How do we identify the involuntary behaviour and what should be the legal aid for such behaviour?

A very pertinent use of Biosciences have been made for coding DNA identification act in foreign countries for identifying the accused and it is very much feasible that in near future biological evidence shall be used for convicting criminals although it requires a very extensive and exhaustive research to establish a significant correlation between the violent behaviour and biological factors.

The journey of this interrelation was given a new direction by Raine through his book

The Anatomy of Violence: The Biological Roots of Crime”. This book has changed the notion of free will, criminal responsibility and justice upside down.

In legal language crime comprises of both an act and a mental element (mens rea) and this mental element is controlled by a plethora of variables. These variables can be broadly classified as biological variables including genetic factors and environmental variables including social factors. There are multiple factors associated with the risk of engaging in criminal behaviour namely low resting heart rate, prenatal exposure to smoking, personality factors like impulsivity, family factors (like parental criminality, poor child upbringing practices, low socio-economic status, maltreatment), poor academic performance, peer rejection etc.

Although there is no direct relation between the genetic composition and a particular antisocial behaviour but the likelihood of a person in indulging violent and antisocial behaviour increases due to the presence of certain genes and moreover the social environment plays a very significant role in provoking and activating such genes. Parenting, in my view, plays a very crucial role among social variables affecting the antisocial behaviour. [2] It is the dual effect of criminal gene and activating socio-environmental factors in accomplishing a particular behavioural act. The modern view focuses on the interaction between the biological characteristics and the stimulus of social environment that activates these biological characteristics. The biological criminologist referred these interactions as biosocial theories of crime.

There are various corporations like Ancestry DNA that have collected the samples from millions of people for health and ancestry purposes.  Such companies can share the information of DNA databases of consumer genetics with law enforcement agencies if ordered by the court. The use of such techniques may pose risk to basic human rights like privacy.

The gateway of biological phenomena in the legal system is the expert evidence rule that is only a committee of experts can give green signal since the biological phenomena is out of the circumference of the understanding of the jury.

According to a report of US Bureau of Justice Statistics about 20% of people living in the developed world face the victimization of anti-social and violent behaviour. In another report of the World Health Organization (WHO) from 2002, it is established that anti-social and violent behaviour is one of the leading cause of incomplete well-being, disease, disability and sometimes even mortality. [3]


Epigenetics simply means the inheritable changes in the traits without any change in the genetic material (genotype) of an individual. There are certain externally mediated modifications in the DNA that may lead to activation and inactivation of particular genes. [4] Usually these modifications are either DNA methylation (addition of methyl group) or histone modification.  For example smoking, an external factor causes DNA methylation and result in cancer. [5] Epigenetics is about the circumstances in the external environment (outside the cells) that may cause the genes to turn off or turn on. Here we are more concerned about behavioural epigenetics where our focus is to understand the externally mediated gene expression and its impact on personality, cognition, mental state and behaviour of the individual. [6]Epigenetics is ubiquitous that is to say every single event (like what we eat? Where do we live? Whom do we interact?) that takes place outside the cell may influence the mechanism of gene expression.

Genetic Structure

What we have got in our genes have nothing to do with our will like someone may have a gene for black hairs and others may have a gene for a blue or green eye. What we are is the outcome of our genetic composition. In various studies, it is found that MAOA and CDH13 gene is present in violent offenders and such genetic profile is absent in non-violent offenders. Genes are responsible for coding proteins and enzymes that may affect the biochemical reactions in the cell, sometimes they may act as promoter or enhancer and sometimes it may act as an inhibitor. This MAOA gene codes for an enzyme monoamine oxidase A which controls the concentration of neurotransmitters (dopamine and serotonin) in the brain. The experts of molecular psychiatry of Finland believe that violent crime could be attributed to the genotypes of the individual. Although these criminals cannot be screened only on the basis of the genes they carry. MAOA also plays a key role in emotional regulation. Monoamine oxidase A (MAOA) genotypic variation has been associated with variation in aggression, especially in interaction with childhood trauma or other early adverse events. [7, 8, 9, 10]

There are various mental disorders like schizophrenia, depression and anxiety that have been linked to genetic factors. Criminal behaviour is also a kind of mental disorder and very much affected by the genetic composition of the individual.

In the Indian penal code, we have come across various liabilities including vicarious liability and joint liability. Now, this is the prime time to think of including the genetic liability in the Indian penal code.

Geneticist should come up with more certain results not only to convict the accused and boosting the justice but also for crime prevention and making the society crime free and a more peaceful place to live in. There are certain behaviour that may induce other behavioural disorders for example attention deficit hyperactivity disorder (ADHD) affects the antisocial and criminal behaviour. This behaviour-behaviour interaction should be considered in crime prevention techniques. One thing should be made very clear is that the genetic factors are not deterministic for criminal behaviour. The genes present in the body simply provide a platform where the crime can flourish if provoked by the certain external stimulus.

We need to put efforts into understanding the underlying mechanism in the development of criminal behaviour.


Gender-based behaviour is a great issue; many of us will relate this to the issue of equality. But perhaps such people are confused between the equal and identical. The two genders can never be identical but yes equality is a fundamental human right irrespective of the gender. The equality of genders is sometimes exaggerated to an extent of making them identical which is against nature. We should talk about equilibrium rather than equality because the equilibrium between the two genders is about rights, duties and justice while the differences between two genders have been taken into account. Contrarily, equality ignores the differences between the genders and hence sometimes not justified. The two genders have different bodily structures, different genetic composition, a different spectrum of hormones flowing in their blood vessels, and obviously different behavioural instincts. The violent behaviour has been associated with Y chromosome and testosterone in the recent past but the correlation between the two is insignificant. Both the XYY condition and the linkage between the androgen levels and aggression are denied by the majority of the legal community as defence. [11, 12] In People v. Tanner, Millard v. State and People v. Yulk court denied the evidence of XYY. In females, premenstrual syndrome (PMS) have been associated with aggression, violence, distorted psychiatric symptoms and even suicide attempts.

Legal implication

In the United States, Supreme Court has allowed law enforcement to collect DNA of arrested persons but not of convicted persons as result of Maryland v. King. DNA analysis has helped the innocents to get released who were in the prisons since as long as 19 years.

The use of biosciences have found its place in police investigation including DNA fingerprinting and lie detector tests but they are still not accepted as evidence by the courts.

According to reports from FBI, DNA as an evidence have been used in the investigation of about 4 lacs cases and DNA analysis is considered to be an important tool in law enforcement.

There are various techniques like an electroencephalogram (EEG), computerized axial tomography (CAT), position emission tomography (PET), single photon emission tomography (SPECT) and magnetic resonance imaging (MRI) that have been used to study the criminal behaviour. Most of these studies lack the strength of correlation to be used as evidence in the court of justice.

In a 2009 criminal trial in the United States, an argument based on a combination of “warrior gene” and history of child abuse was successfully used to avoid a conviction of first-degree murder and the death penalty; however, the convicted murderer was sentenced to 32 years in prison. [13, 14]The general presumption in criminal law is that behaviour is a consequence of free will although the insanity defence is widely accepted. [15, 16] Following are the medical evidence that have been introduced by the criminal defendants.

Uncontrolled and assaultive behaviour due temporal lobe epilepsy, Brain Disease, Schizophrenia, Mood disturbance caused by extreme stress, Post-Partum Psychosis. [17, 18, 19, 20, 21, 22]

Family and Adoption Studies

Family studies have also given strength to genetic factors especially the twin studies concludes the genetic cause of criminality. The likelihood of criminal and antisocial behaviour among monozygotic twins is higher as compared to dizygotic twins. This observation establishes that the crime is more genetically mediated. On the other hand, the adopted children are separated from their biological parents at an early stage of childhood and maybe influence from the behaviour of the adopting parents. This forms the basis of socio-environmental factors affecting behaviour.

Moffitt suggests that life-course-persistent antisocial behaviour may have an underlying biological basis, whereas adolescent limited antisocial behaviour may be better explained by situational environmental factors. [23]


In eugenics, we try to improve the genetic composition of the human race by employing selective breeding. This can be achieved in two ways, first one is to discourage the reproduction of individuals having the defective genetic material to decline their population and the second one is to motivate the rate of reproduction of individuals having better genetic material thus increasing the population of enhanced genetic traits. The former method is termed as positive eugenics and the latter is termed as negative eugenics. This analogy can be found in the provision of punishments under various penal codes of different countries including the Indian Penal Code. Capital punishment and lifetime imprisonment can be a part of negative eugenics by either declining the criminals in the society or capping the reproduction of individuals having criminal psyche as seen in life imprisonment. After World War II, Japan has been the victim of eugenics when about 25000 citizens were sterilised under the government’s Eugenic Protection Law.[24]


There are multiple studies that show the correlation between the behaviour, psyche and the concentration of neurotransmitters in the brain with a greater emphasis on dopamine, serotonin and norepinephrine. Neurotransmitters are the biochemical that plays a vital role in the mechanism of transmission of electrochemical impulses within the brain and processing of plethora of information present in the brain of the individual. Statistically, significant correlation has been observed between genetic defects in neurotransmitters (dopamine and serotonin) and violent behaviour. It has also been associated with certain drug abusers in various studies. These genetic variations affecting the metabolism of neurotransmitters usually causes impulsive behaviour, and this impulsive behaviour sometimes starts a cascade of various other events in the spectrum of the anti-social and criminal mentality.[25, 26]


Aggression is a sexually dimorphic response, in males’ gonadal steroids like testosterone is considered to stimulate social aggression. Statistical evidence say that men are actively involved in violent crimes and the no. of males is higher than females in criminal activity. The correlation between the levels of circulating testosterone and criminal offending is well established. [27, 28, 29, 30, 31]

Environmental Toxins

A plethora of toxins have been discharged into the different layers of environment after the industrialization, these toxins are ubiquitous and present in every fibre of the environment. They may include heavy metals and other synthetic organic compounds and have been found to affect the behaviour of an individual. It integrates the biological with sociological and criminological theories. Biological investigations are based on the fact that criminal behaviour is highly associated with frontal lobe of the brain and is very sensitive to environmental toxins.   [32]

Social Factors

These are the factors that stimulate and activate the biological and genetic factors. In the absence of social variables, biological variables could remain dormant. It is the responsibility of the family and the society as a whole to make the environment that does not interact with the criminal genes. A positive environment may nullify and annihilate the effect the genetic composition of the criminals in the society. [33, 34]


There are various questions that we need to answer i.e. is there a genetic liability of crime? Are we punishing an individual for an involuntary act? Is there an innate tendency towards crime? There is an emergency to develop a legal and ethical framework to address all these issues in order to enhance the justice.


1- Wolfgang, Cesare Lombroso, 1835-1909, in PIONEERS IN CRIMINOLOGY

232, 232 (H. Mannheim ed. 1973).

2- Byrd AL, Manuck SB. Biol Psych. 2014:75.

3- Psychological Bulletin Copyright 2005 by the American Psychological Association 2005, Vol. 131, No. 4, 533–554 0033-2909/05/$12.00 DOI: 10.1037/0033-2909.131.4.533

4- https://www.whatisepigenetics.com/fundamentals/

5- https://www.livescience.com/37703-epigenetics.html

6- https://www.whatisepigenetics.com/what-is-epigenetics/

7- http://www.sinobiological.com/MAOA-Monoamine-oxidase-A-Protein-a  2783.html?gclid=Cj0KCQiA28nfBRCDARIsANc5BFACZ7fdpDz7Yd9L4R1hqhYmXM4L8xQKEnrmaCFi5gg4n2gBAozRAmIaAsRcEALw_wcB

8-Huang SY, et al. (2009) Association of monoamine oxidase A (MAOA) polymorphisms and clinical subgroups of major depressive disorders in the Han Chinese population. World J Biol Psychiatry. 10 (4): 544-51.

9- Guo G, et al. (2008) The VNTR 2 repeat in MAOA and delinquent behavior in adolescence and young adulthood: associations and MAOA promoter activity. Eur J Hum Genet. 16(5): 626-34

10- McDermott R, et al. (2009) Monoamine oxidase A gene (MAOA) predicts behavioural aggression following provocation. Proc Natl Acad Sci. 106 (7): 2118-23.

11- Barber N (2010-07-13). “Pity the poor murderer, his genes made him do it” Psychology Today. Blog: “The Human Beast: Why we do what we do”. Retrieved 2010-10-17.

12- Turner, Robinson, Lang & Purvis-Smith, Preventive Screening for the Fragile X Syndrome, 315 NEW ENG. J. MED. 607, 607-09 (1986)

13- Koepf, Ishihara & Hauschka, An XYY Human Male, [1961] 2 LANCET 488, 488-89.

14- Hagerty BB (2010-07-01). “Can Your Genes Make You Murder?” News > Science > Inside The Criminal Brain. National Public Radio.Retrieved 2010-10-17.

15- Keilitz, Researching and Reforming the Insanity Defense, 39 RUTGERS L. REV. 289, 293-303 (1987)

16- L. Taylor, born to crime: the genetic causes of criminal behaviour 17-20 (1984);

17- Psychomotor Epilepsy and Aggressive Behavior, 28 ARCHIVES GEN. PSYCHIATRY 210, 210 (1973).

18- V. Mark & F. Ervin, Violence AndThe Brain 148 (1970).

19- L. Caplan, The Insanity Defense And The Trial Of John W. Hinckley, JR. 82 (1984).

20- See Both Sides Rest Their Cases In Moscone Murder Trial, N.Y. Times, May 15, 1979, At A14, Col. 6; Ex-Supervisor Held Unable To Tell Right From Wrong, N.Y.Times, May 8, 1979, At A16, Col. 6

21- Sullivan, Jury, Citing Mother’s Condition, Absolves Her in 2 Babies’ Deaths, N.Y. Times, Oct. 1, 1988, at 29, col. 2.

22- Mansnerus, The Darker Side Of the ‘Baby Blues,’ N.Y. Times, Oct. 12, 1988, at Cl, col. 1.

23- Moffit, T.E. (1987). Parental mental disorder and offspring criminal behavior: An adoption study. Psychiatry: Interpersonal and Biological Processes, 50, 346-360.

24-  http://www.scielo.br/scielo.php?pid=S010412902018000200354&script=sci_arttext&tlng=en

25- Ambar, G., & Chiavegatto, S. (2009). Anabolic-androgenic steroid treatment induces behavioral disinhibition and downregulation of serotonin receptor messenger RNA in the prefrontal cortex and amygdale of mice. Genes, Brain and Behavior, 8, 161-173.

26- Celada, P., Puig, M. V., & Artigas, F. (2013). Serotonin modulation of cortical neurons and networks. Frontiers in Integrative Neuroscience, 7, 25.

27- Moffitt, T. E., Caspi, A., Rutter, M., & Silva, P. A. (2001). Sex differences in antisocial behav-iour: Conduct disorder, delinquency and violence in the Dunedin longitudinal study.

Cambridge: Cambridge University Press (http://doi.org/10.1017/CBO978051149057

28- Felson, R. B. (2002). Violence and gender re-examined. DC: American Psychological Association

29- Steffensmeier, D., & Allan, E. (1996). Gender and crime: Toward a gendered theory of female offending. Annual Review of Sociology,22,459–487.

30- Dabbs, J. M., & Dabbs, M. G. (2000). Heroes, rogues, and lovers: Testosterone and behavior. McGraw-Hill.

31- Hoskin, A. W., & Ellis, L. (2015). Fetal testosterone and criminality: Test of evolutionary neuroandrogenic theory. Criminology53(1), 54–73 (http://doi.org/10.1111/1745-9125.12056).

32- http://criminal-justice.iresearchnet.com/criminology/theories/biological-theories-of-crime/16/

33- Farrington DP. Predictors, causes and correlates of male youth violence. In: Tonry M, Moore M, editors. Youth violence. Chicago: University of Chicago Press; 1998. p.421-75.

34- Schraiber LB, D’Oliveira AF, Couto MT. Violência e saúde: estudoscientíficosrecentes. Rev SaudePublica. 2006;40(n Esp):112-20.