General Neuroscience

Psychopathy: Finding Clarity in the Grey

Saffanat Sumra


In the 1800s, being neurodivergent  was a common reason behind an individual’s exclusion from society. Today, we understand that having a mental illness is not an alienating notion, but rather a realm of neuroscience which is so complex that we often misunderstand certain conditions, resulting in massive stigma around certain mental illnesses. One particular mental disorder which has often been misunderstood, frequently portrayed as violent and deceptive, is the Antisocial Personality Disorder, also referred to as Psychopathy. In general, people have fabricated all sorts of definitions for Psychopathy, some being true while many others are guided by myths. This article shall elucidate psychopathy from a biological as well as a social standpoint and raise multiple questions over the course of its analysis.

Defining Psychopathy

In clinical terms, doctors often refer to psychopathy as being defined as Antisocial Personality Disorder {ASPD}, although there continue to be arguments regarding the validity of the two being the same disorders. According to the Mayo Clinic, Antisocial Personality Disorder results when  “a person consistently shows no regard for right and wrong and ignores the virtues and feelings of others. People with antisocial personality disorder tend to antagonize, manipulate, or treat others harshly or with callous indifference” [1]. In layperson's terms, people suffering from this type of disorder are usually those who are unable to feel empathy for other people or even guilt for their harmful actions.

There are certain key symptoms shared by most psychopaths. For instance, every psychopathic individual has narcissistic tendencies such as  lack of empathy, a grandiose sense of self-worth, high self-esteem, feeling entitled and arrogant, and almost always seeking validation [6]. They are individuals who do not feel remorse whenever they commit an act potentially harmful to those around them. These actions have a wide range from stealing someone’s food to setting a house on fire. Regardless of the activity, the feeling of guilt is almost always absent. Hollywood and fiction novels have often portrayed psychopaths to be similar to serial killers, assassins, or even rapists— a very narrow perspective on the condition. However, it's likely that we are not aware of psychopaths or sociopaths who exist around us and whether assigning them the title of this disorder is the correct or ethical thing to do.


Psychopathy vs. Sociopathy

Psychopathy is often confused with Sociopathy, since both of these can be defined in terms of Antisocial Personality Disorder. However, in an interview conducted by the Medcircle, Dr. Ramani, a clinical psychologist based in California, points out the key difference between someone considered a psychopath and a person who is considered a sociopath. She says “A psychopath is born, and a sociopath is made.” While psychopathic individuals may have had remorseless and arrogant tendencies since birth, sociopaths have developed these symptoms over the years [2]. 

Sociopathic individuals’ circumstances render them to develop such mechanisms as a mode of survival in the arduous world that they grew up in. Sociopaths bear strong resemblances with psychopaths in terms of having a narcissistic demeanor and their poor treatment of other individuals. In fact, it is a term more commonly used throughout social media and television as well, with one of its most significant and noticeable uses being in the popular novel series and show  Sherlock Holmes, where the protagonist Holmes designates himself as a “highly functioning sociopath” in order to account for his indifferent and arrogant, yet considerate attitude towards others.


Biological Explanations Behind Psychopathy

Another interesting point mentioned by Dr. Ramani was about the biological difference between someone who is a psychopath and any other ordinary person or even a sociopath. She says that psychopaths “are actually believed to have slightly different autonomic nervous systems.” Our body is mainly composed of the central nervous system (the brain and spinal cord) and the autonomic nervous system, which is responsible for functions, such as breathing, which are not in our conscious control.  The autonomic nervous system is further divided into the parasympathetic and the sympathetic nervous system, the latter producing responses commonly known as the “fight or flight response”, which is triggered in times of danger or extreme anxiety [7]. For instance, when a person commits a felonious act, their sympathetic nervous system may be activated, producing symptoms such as an increased heart rate, increased breathing, and dilated pupils. A psychopath, on the other hand, does not experience this similar rush of hormones, which is why they are often able to lie on lie detector tests [8]. 

With regard to the genes specifically contributing to APD, behavioral genetics is rather controversial when studying personality disorders. There have been multiple real-life situations employing the existence of a genetic link to psychopathic tendencies [3]. Case in point: In 2009, an Italian appeal court decided to cut down the sentence of a convicted murderer by one year on the grounds that he had a version of the MAOA gene. This gene provides instructions for the formation of Monoamine oxidase A, or the MAOA enzyme which helps in the breakdown of neurotransmitters such as serotonin and dopamine that are vital in regulating mood and emotions [10]. Possessing an alternate version of the MAOA gene influences this regulation, promoting aggression and violence. 

According to Anthony Walsh from the Criminal Justice Department at Boise State University in Idaho, making such genetic determinisms is “plain stupid”, unless the condition is one such as  Down’s Syndrome, in which an individual is proven to have a mild to moderate intellectual disability and executive functioning [3]. In fact, psychopaths are believed to not just be biologically disposed with their condition— the environment that they grow up in plays a critical role in the further development of psychopathic traits,  similar to how sociopaths develop antisocial tendencies.

The molecular mechanisms inside the brain of a psychopath continue to remain unclear. Previous studies suggest abnormal glucose metabolism and opioidergic neurotransmission as factors contributing to violence, which is often seen in psychopaths. A very influential study was conducted on cortical neurons and astrocytes from 6 violent offenders, three non-psychotic individuals, who were involved in substance abuse, and 6 healthy subjects [6]. Their goal was to prove that alterations between the gene expressions and immune responses of each of these individuals do exist. In terms of the different types of neurons, the study found that there was an upregulation of RPL10P9 and ZNF132, and downregulation of CDH5 and OPRD1. These aforementioned genes may be relevant to lack of empathy and remorse as past studies have established connections between the up and downregulation of these genes with how psychopaths commonly react and interact with those around them [9]. While this study does establish a connection between the abnormal genetic expression unique to the neurons in the brains of psychopaths, it was conducted on a fairly small sample size, which is inevitable due to the difficulty in acquiring data from the brains of incarcerated offenders. The experimental subjects in the study represented only a fraction of the entire spectrum of psychopathy, ranging from some very strong symptoms to being almost undetectable.

Such a broad spectrum of symptoms blurs the boundary defining who may be considered a psychopath and who may not. Are the traits laid down by the DSM really the best standard of diagnosing antisocial personality disorder? Looking back in time, a famous figure associated with the study of psychopathy was Robert Hare, a psychologist who extensively studied psychopathy and worked at the maximum-security British Columbia Penitentiary. He created the famous Psychopathy Check-List Revised or more commonly the PCL-R, for researchers back in the 1980s [5]. Even today, the checklist is considered to be the gold standard for diagnosing psychopathy and is employed by scientists and physicians across a wide range of fields from medicine and research to law and order. 


Looking Ahead: Current Progress in Psychopathy Research

From the early days of executing people for exhibiting neurodivergence, to the 21st century when the nature of extreme antisocial personality remains indefinite, there is a wide scope for behavioral research in the realm of psychopathy. While the amount of time required to find clarity in the grey area of psychopathy cannot be determined yet, current studies are working towards increasing awareness about the biological and social facts behind this deceptive disorder.


  1. Mayo Clinic. (2019, December 10). Antisocial Personality Disorder. Retrieved: 06/23/2020.

  2. MedCircle. (2018, June 25). Narcissist, Psychopath, or Sociopath: How to Spot the Differences. Retrieved: 06/22/2020.

  3. Hunter P. (2010). The psycho gene. EMBO reports. 11(9), 667–669. Retrieved: 06/18/2020.

  4. Tiihonen, J., Koskuvi, M., Lähteenvuo, M., Virtanen, P. et al. (2019). Neurobiological roots of psychopathy. Molecular Psychiatry, 10.1038/s41380-019-0488-z. Advance online publication. Retrieved: 06/02/2020.

  5. Hare, R. D., & Neumann, C. S. (2006). The PCL-R Assessment of Psychopathy. New York, New York: The Guilford Press. Retrieved: 06/22/2020.

  6. Fan, Y., Wonneberger, C., Enzi, B., de Greck, M., Ulrich, C., Tempelmann, C., Bogerts, B., Doering, S., & Northoff, G. (2011). The narcissistic self and its psychological and neural correlates: an exploratory fMRI study. Psychological medicine, 41(8), 1641–1650. Retrieved: 06/24/2020.

  7. McCorry L. K. (2007). Physiology of the autonomic nervous system. American journal of pharmaceutical education, 71(4), 78. Retrieved: 06/20/2020.

  8. Patrick, Christopher & Iacono, William. (1989). Psychopathy, Threat, and Polygraph Test Accuracy. Journal of Applied Psychology. 74. 347-355. 10.1037/0021-9010.74.2.347. Retrieved: 06/20/2020.

  9. Blair, R. (2003). Neurobiological basis of psychopathy. British Journal of Psychiatry, 182(1), 5-7. doi:10.1192/bjp.182.1.5. Retrieved: 06/20/2020.

  10. Brunner HG, Nelen M, Breakefield XO, Ropers HH, van Oost BA (1993). Abnormal behavior associated with a point mutation in the structural gene for monoamine oxidase A. Science. Retrieved: 06/22/2020.

  11. Sánchez, Beatriz & Herrero, Juan & Velasco, Judith & Rodríguez-Díaz, Francisco (2015). A contrastive analysis of the factorial structure of the PCL-R: Which model fits best the data?. The European Journal of Psychology Applied to Legal Context. Retrieved: 06/30/2020.

Saffanat Sumra

Saffanat Sumra

Hi! I am Saffy, a second year undergraduate studying Neurobiology and Toxicology at the University of California, Berkeley.