Articles about badly behaved people and how to spot them are common. You don’t have to Google or scroll too much to find headlines such as 7 signs your boss is a psychopath or How to avoid the sociopath next door.

You’ll often see the terms psychopath and sociopath used somewhat interchangeably. That applies to perhaps the most famous badly behaved fictional character of all – Hannibal Lecter, the cannibal serial killer from The Silence of the Lambs.

In the book on which the movie is based, Lecter is described as a “pure sociopath”. But in the movie, he’s described as a “pure psychopath”. Psychiatrists have diagnosed him with something else entirely.

So what’s the difference between a psychopath and a sociopath? As we’ll see, these terms have been used at different times in history, and relate to some overlapping concepts.

What’s a psychopath?

Psychopathy has been mentioned in the psychiatric literature since the 1800s. But the latest edition of the Diagnostic Statistical Manual of Mental Disorders (known colloquially as the DSM) doesn’t list it as a recognised clinical disorder.

Since the 1950s, labels have changed and terms such as “sociopathic personality disturbance” have been replaced with antisocial personality disorder, which is what we have today.

Someone with antisocial personality disorder has a persistent disregard for the rights of others. This includes breaking the law, repeated lying, impulsive behaviour, getting into fights, disregarding safety, irresponsible behaviours, and indifference to the consequences of their actions.

To add to the confusion, the section in the DSM on antisocial personality disorder mentions psychopathy (and sociopathy) traits. In other words, according to the DSM the traits are part of antisocial personality disorder but are not mental disorders themselves.

US psychiatrist Hervey Cleckley provided the first formal description of psychopathy traits in his 1941 book The Mask of Sanity. He based his description on his clinical observations of nine male patients in a psychiatric hospital. He identified several key characteristics, including superficial charm, unreliability and a lack of remorse or shame.

Canadian psychologist Professor Robert Hare refined these characteristics by emphasising interpersonal, emotional and lifestyle characteristics, in addition to the antisocial behaviours listed in the DSM.

When we draw together all these strands of evidence, we can say a psychopath manipulates others, shows superficial charm, is grandiose and is persistently deceptive. Emotional traits include a lack of emotion and empathy, indifference to the suffering of others, and not accepting responsibility for how their behaviour impacts others.

Finally, a psychopath is easily bored, sponges off others, lacks goals, and is persistently irresponsible in their actions.

So how about a sociopath?

The term sociopath first appeared in the 1930s, and was attributed to US psychologist George Partridge. He emphasised the societal consequences of behaviour that habitually violates the rights of others.

Academics and clinicians often used the terms sociopath and psychopath interchangeably. But some preferred the term sociopath because they said the public sometimes confused the word psychopath with psychosis.

“Sociopathic personality disturbance” was the term used in the first edition of the DSM in 1952. This aligned with the prevailing views at the time that antisocial behaviours were largely the product of the social environment, and that behaviours were only judged as deviant if they broke social, legal, and/or cultural rules.

Some of these early descriptions of sociopathy are more aligned with what we now call antisocial personality disorder. Others relate to emotional characteristics similar to Cleckley’s 1941 definition of a psychopath.

In short, different people had different ideas about sociopathy and, even today, sociopathy is less-well defined than psychopathy. So there is no single definition of sociopathy we can give you, even today. But in general, its antisocial behaviours can be similar to ones we see with psychopathy.

Over the decades, the term sociopathy fell out of favour. From the late 60s, psychiatrists used the term antisocial personality disorder instead.

Born or made?

Both “sociopathy” (what we now call antisocial personality disorder) and psychopathy have been associated with a wide range of developmental, biological and psychological causes.

For example, people with psychopathic traits have certain brain differences especially in regions associated with emotions, inhibition of behaviour and problem solving. They also appear to have differences associated with their nervous system, including a reduced heart rate.

However, sociopathy and its antisocial behaviours are a product of someone’s social environment, and tends to run in families. These behaviours has been associated with physical abuse and parental conflict.

What are the consequences?

Despite their fictional portrayals – such as Hannibal Lecter in Silence of the Lambs or Villanelle in the TV series Killing Eve – not all people with psychopathy or sociopathy traits are serial killers or are physically violent.

But psychopathy predicts a wide range of harmful behaviours. In the criminal justice system, psychopathy is strongly linked with re-offending, particularly of a violent nature.

In the general population, psychopathy is associated with drug dependence, homelessness, and other personality disorders. Some research even showed psychopathy predicted failure to follow COVID restrictions.

But sociopathy is less established as a key risk factor in identifying people at heightened risk of harm to others. And sociopathy is not a reliable indicator of future antisocial behaviour.

In a nutshell

Neither psychopathy nor sociopathy are classed as mental disorders in formal psychiatric diagnostic manuals. They are both personality traits that relate to antisocial behaviours and are associated with certain interpersonal, emotional and lifestyle characteristics.

Psychopathy is thought to have genetic, biological and psychological bases that places someone at greater risk of violating other people’s rights. But sociopathy is less clearly defined and its antisocial behaviours are the product of someone’s social environment.

Of the two, psychopathy has the greatest use in identifying someone who is most likely to cause damage to others.

Bruce Watt, Associate Professor in Psychology, Bond University and Katarina Fritzon, Associate Professor of Psychology, Bond University

This article is republished from The Conversation under a Creative Commons license. Read the original article.