Psychopath vs Sociopath: A Writers Guide

When we talk about serial killers in fiction (and in real life) we tend to talk in terms of ‘psychopath’ or ‘sociopath’ and, often, interchangeably. Let’s have a look at what makes them similar, but also they behave differently and what we might need to consider if we are writing characters with these traits.


First, let’s dispel some myths.

  • Not all psychopaths or sociopaths are killers, though most serial killers are thought to be psychopaths
  • The traits listed below for psychopaths actually help many of them enjoy high-level positions in their place of employment (again, without killing anybody!)


The Similarities

Both psychopaths and sociopaths are described under the umbrella of ‘Anti-Social Personality Disorder’:

‘Antisocial personality disorder is a particularly challenging type of personality disorder, characterised by impulsive, irresponsible and often criminal behaviour. Someone with antisocial personality disorder will typically be manipulative, deceitful and reckless, and won’t care for other people’s feelings.’ NHS definition


In what ways are they similar? Both may:

  • exhibit violent behaviour
  • be unable to control their anger
  • lack feelings of remorse or guilt
  • exploit, manipulate or violate the rights of others
  • demonstrate disregard for core societal rules, laws
  • behave irresponsibly and show disregard for normal social behaviour
  • blame others for problems in their lives
  • repeatedly break the law and/or have a history of conduct disorder

In the article to follow, I am assuming that you want to read up on these two disorders for crime fiction writing purposes. I, therefore, explore the different ways a psychopath or sociopath may carry out a violent crime.  I don’t intend to cause any offence to anyone who displays these traits J

Scroll to the bottom to see an infographic summary of this guide!


The Psychopath

You could be forgiven for thinking there are murderous psychopaths around every corner, considering the proliferation of characters depicted as psychopaths in TV, film and fictional novels. Though not quite that prolific, 1% of the population are thought to be psychopaths which, when you think about it is 1 in every 100 people you come across! In fact, up to 4% of all CEOs are thought to be psychopaths… scary stuff!



A psychopath is thought to be the product of a mix of faulty genetics, biology and serious childhood trauma or abuse:

genetic makeup + brain patterns + childhood trauma = psychopath!

It is thought that an under-developed paralimbic system (responsible for controlling impulse, goal-seeking, motivation and emotional processing) is the trigger here. fMRI scans show the differences between normal brain and psychopathic brain because the paralimbic tissue shows evidence of thinning in a suspected psychopathic brain.

A clinician could also test for psychopathy using the Dr Hare’s ‘PCL-R test’ (Psychopathic Checklist – Revised) which measures patients against 20 traits:

  • glib and superficial charm
  • grandiose (exaggeratedly high) estimation of self
  • need for stimulation
  • pathological lying
  • cunning and manipulativeness
  • lack of remorse or guilt
  • shallow affect (superficial emotional responsiveness)
  • callousness and lack of empathy
  • parasitic lifestyle
  • poor behavioural controls
  • sexual promiscuity
  • early behavioural problems
  • lack of realistic long-term goals
  • impulsivity
  • irresponsibility
  • failure to accept responsibility for own actions
  • many short-term marital relationships
  • juvenile delinquency
  • revocation of conditional release
  • criminal versatility

If you’re interested in finding out more about this test, you can have a read of more info here or even take a psychopath test here!


Psychopathic Traits

Research shows that psychopaths are overwhelmingly male. They are also on the extreme end of the spectrum of personalities that fall under the Anti-Social Personality Disorder umbrella.

Our psychopath is likely well-educated and has a high IQ – they could have a great career. They lack empathy entirely but may be able to mimic it as an emotion. They are also renowned for being incredibly charming – how might this have helped your killer to gain access to the victim? Where did they meet?

They are a controlled, highly manipulative individual who can become wholly fixated on a task. These traits are mirrored in the state of the crime scene: minimal physical evidence has been left behind.

This person cannot make close personal attachments and remain cool under pressures like punishment, fear, stress or disapproval. Additionally, they cannot detect emotional nuances in language or facial expressions; for all of these reasons, the usual threats made under police interview are unlikely to phase a psychopath. How will your fictional detective tease out a confession if one is needed?

Their inability to respond to punishment means psychopaths are six times more likely to re-offend following a stint in prison. Is your psychopath already known to police?


Not to be confused with: ‘Psychotic’ – someone suffering from a manic depressive disorder.

Famous psychopaths: Adolf Hitler, Ted Bundy, Hannibal Lecter

Find out more: Watch Jim Fallon’s TED talk ‘Exploring the Mind of a Killer’ and also Jon Ronson’s ‘Strange Answers to the Psychopath Test’. If you’re interested in the fact about CEOs often being psychopaths, you’ll also love this article!



The Sociopath

You are much more likely to have met a sociopath as 4% of the population are classified as this.



Trauma or abuse occurring before puberty is the key factor in determining sociopathy, as is early institutionalisation; perhaps your killer has spent time in a mental institution or prison. If we think of psychopaths and sociopaths as opposites, as the nature versus nurture debate, sociopaths are the nurture; they are not born as such but learn the behaviours because of their abusive upbringing.


Sociopathic Traits

Unlike the psychopathic counterpart, a sociopath is unlikely able to hold down a steady job for long and may be uneducated. You will need to build a back history of short stints at various jobs: What kinds of occupations would your sociopath likely have?

A sociopath is most likely a loner from a poor socioeconomic background, often ending up on the streets and with problems with drug addiction.

Having said this, the sociopath could blend into society as they are able to form attachments where a psychopath does not; people of a sociopathic nature enjoy happy, loving relationships in our societies. Does your killer have friends or perhaps a lover?

The personality of a sociopath is characterised as erratic, angry and prone to rage; they respond to ‘slights’ by getting even with the world. As such murders committed by this type of person are often spontaneous in nature; this means a messy crime scene and evidence will more than likely be left behind because the killer has not planned to kill.

A police interview will be easier with a sociopath because they are vulnerable to stress, anxiety and shame where a psychopath is not. How might an interviewer use these weaknesses to glean a confession from a sociopath?


Famous sociopaths: Josef Mengele, Diazien Hossencofft, Sherlock Holmes

Find out more: Read ‘Confessions of a Sociopath’ by M. E. Thomas here. Also, ‘The Sociopath Next Door: The Ruthless Versus the Rest of Us’ by Martha Stout here.


For further reading and the sources used to inform my article, go to the Criminal Psychology section of my Non-Fiction Books and Journal Sources list!

A handy infographic by Healthtopia:

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