Study reveals surprising habit that psychopaths are more likely to do

A new study analysed a group of clinically diagnosed psychopaths and uncovered many share this one thing in common. Do you have it too?

Are you a stone-cold psychopath? The answer could be right in your hands.

Canadian researchers have analysed the finger lengths of volunteers with clinically diagnosed psychiatric issues in order to determine whether psychopathy is “biologically rooted.”

The team made a surprising discovery, finding that those whose index fingers are shorter than their ring fingers are more likely to have a diagnosed psychiatric disorder, The New York Post reports.

The results of the study have now been published in the February edition of The Journal of Psychiatric Research.

The team started out by noting that those who have a lower 2D:4D-ratio — ie: a shorter index finger and a longer ring finger — are already known to be more commonly associated with “Dark Triad” traits and aggressive behaviour.

Those whose index fingers are shorter than their ring fingers are more likely to have a diagnosed psychiatric disorder. Picture: iStock

These traits are “highly socially discouraged attitudes, namely Machiavellianism, narcissism and psychopathy”.

The paper noted that people who score high on the “Dark Triad” scale have “also scored high on mental toughness and sports performance, but also on various types of negative psychosocial and psychological outcomes, including intolerance of uncertainty, anxiety sensitivity callous affect, and interpersonal manipulation”.

For the scientific study, the researchers recruited 80 volunteers: 44 with psychiatric issues and 36 healthy individuals without any diagnosed mental conditions.

An analysis of their hands confirmed that “compared to healthy controls, individuals with a clinically diagnosed psychiatric issue were more likely to have a shorter index finger and longer ring finger”.

Real life psychopaths are often very different to the ones portrayed on screen. Picture: Courtesy Everett Collection

The investigation uncovered that, compared to the healthy controls, individuals with a clinically diagnosed psychiatric issue were more likely to have a shorter index finger and longer ring finger.

The results also confirmed that lower “2D:4D-ratios were associated with higher ‘Dark Triad’ traits”.

But the study’s lead author, Serge Brand, is warning people with shorter index fingers not to fret, saying it’s still very common.

A lower 2D:4D-ratio is also associated with a prenatally higher testosterone and lower oestrogen exposure during the first trimester the foetal stage, according to Brand.

“The more an adult participant had signs of psychopathology, the more it appeared that this adult has been exposed to higher testosterone concentrations and lower oestrogen concentrations during the prenatal period of life,” Brand told PsyPost.

However, he added: “It is important to understand that the finger lengths-ratio as a proxy of a specific exposure to prenatal sex steroids should not be understood as a person’s irrevocable fate.”

Melbourne psychologist Carly Dober previously shared 5 common traits of a psychopath. Picture: Supplied

Melbourne psychologist Carly Dober previously shared five common traits of a psychopath with news.com.au, explaining the real life reality of a person with the condition is vastly different to what plays out in Hollywood films, such as American Psycho or the modern TV portrayal of Ted Bundy.

“I think we need to keep in mind that films that romanticise or glamorise crimes have a lot of creative freedom, and are meant to entertain and not educate,” Ms Dober said.

“Most people who have a high degree of psychopathic traits did not choose to be this way.

“We know that personality forms during childhood. Their experience has likely been shaped by inherited genes, as well as life situations and experiences.

“So while psychopathic traits do lead to people being more vulnerable to committing crimes, not all will do this.

Ted Bundy, played here by Zac Efron, is one of the most famous psychopaths in the world.

Five common traits of a psychopath

1. They often lie, deceive and manipulate to get what they want, usually for profit of self-amusement

2. They will engage in impulsive behaviour

3. They are often irritable and aggressive, may frequently assault others or gets into fights

4. Show a blatant disregard for safety, both of themselves and of others

5. Display a total lack of remorse for their actions.

The psychologist points out that these traits can arise in most people to a normal degree at some point in their lives, in different contexts.

In addition to these behavioural traits, there are also some possible physical signs that could indicate someone is a psychopath.

— With The New York Post