The Eysenck Model: the Personality Profile of a Criminal

The Eysenck model is one of the most important pieces of research on personality that has ever been done. You’ll see that this model gives a very broad vision of what exactly defines personality.

Criminality was (and is) one of the biggest unknowns about human beings that we’ve attempted to explain. Sometimes we’re successful, and other times we don’t come up with any good answers.

But one of the places that we’ve gone the farthest in is how it’s related to personality. That’s why today we’re going to focus on explaining the Eysenck model of a criminal personality.

The Greek origins of theories of personality

Most theories of personality have their roots in Greek philosophy. One of the most important figures people have used as a reference point is Hippocrates. He developed his theory of the four temperaments based on Empedocles’ theory of the four elements.

Empedocles thought that everything in nature was made up of four basic elements: air, earth, fire, and water. From there, Hippocrates connected those four elements to the fluids in our body.

He thought there were four fluids that had specific characteristics, and a person’s temperament depended on which ones they had more of.

The Eysenck model of personality

What makes the Eysenck model so important is the characteristics that make it up: it’s dispositional, hierarchical, dimensional, and psychobiological. And they are all inter-connected.

Dispositional

People say that the model Eysenck came up with is dispositional, since “psychological traits” play a central part in his theory. To put it simply, a trait or a disposition is the tendency you have to behave in a similar way in similar situations. 

That is, there’s a certain kind of inertia in you that comes about from your specific personal qualities. And that leads you to always behave the same way in response to similar stimuli. Thus there’s a relationship between behaviors and situations. 

Hierarchical

The Eysenck model proposes a pyramid structure for how we create our personalities. That means it starts out with the most specific blocks and goes down to the broadest, most general one:

• Specific response: your response to a particular context or situation.
• Habitual response: in similar situations, you always give the same specific response. That is, a group of specific responses that you always give in the same context makes up your habitual response.
• Trait: the group of habitual responses that you give in different contexts makes up a trait. In other words, you’ll have a tendency to behave in a similar way in a specific context.
• Dimension: multiple traits join together under a much broader concept, a dimension.

Dimensional

In the Eysenck model, there are three main dimensions: extroversion, neuroticism, and psychoticism. These three come together to form a specific personality type. They also give shape to a three-dimensional space where everyone fits in depending on how much of each of these dimensions they have in their personality.

In this model, personality is the outcome of the combination of these three dimensions. By itself, each dimension has its own two-dimensional plane. That means they all have opposites.

• Extroversion (vs. introversion): An extrovert is a sociable, lively, dominant person always looking for new sensations. On the other hand, an introverted person is reserved, distant, etc.
• Neuroticism (vs. stability): Neuroticism has to do with unstable moods. This is related to how likely a person is to suffer from mood disorders. What stands out here are feelings of guilt, anxiety, low self-esteem, being emotional, etc.
• Psychoticism: this is a two-sided response: you either have it or you don’t. The people who do are usually cold, impersonal, aggressive, antisocial, and not very empathetic.

Psychobiological

Now, for every dimension, there’s also a specific physiological and hormonal structure. These structures also line up differently depending on the dimension they’re related to.

• Extroversion: this goes along with your ascending reticular activating system (ARAS), based on the activation or inhibition of your internal cortical systems. That’s why someone with a high degree of extroversion has a strong, internal cortical inhibition. That is, they have a hard time seeing things as risks, which leads to external, uninhibited behavior.
• Neuroticism: this dimension goes along with activity in your limbic system (connected to the autonomic nervous system, or ANS). Its job is to regulate your emotions. It’s also made up of brain structures like the amygdala and hippocampus, among others. A high degree of neuroticism means a lot of limbic activity. That, in turn, means that your emotions flare up more quickly and take longer to go away.
• Psychoticism: this is the least developed dimension, and there’s no associated physiological system yet. But there is some kind of relationship between it and serotonin production.

Criminal personality and the Eysenck model

To explain criminal personality using this model, you have to have understand “crime.” A crime involves taking on certain risks and extreme behaviors, like lack of concern for other people’s well-being and property. That’s why, according to the Eysenck model, this is the combination that makes up a criminal personality: 

• First, there is a high degree of extroversion. Boldness and a lack of concern (basic traits of extroversion) are two major elements in committing a crime. If we’re being honest, you have to be brave to rob a store, for example.
• Secondly, a criminal is also defined as having low levels of neuroticism. Their limbic system doesn’t turn on as fast when it receives stimuli. That has a very specific result in the moment they think about committing a crime. It means they won’t be looking at the future consequences of their actions. On top of that, the stimuli doesn’t activate the ANS’s sympathetic nervous system. That will stop them from feeling guilty and regretting what they did later on.
• Lastly, someone who has committed a crime will have a high degree of psychoticism. That means they don’t feel empathy and are unconcerned about what they’ve done.

The Eysenck model provides general explanations for a wide range of different personalities. It all depends on the combinations. After all, there’s no fixed “quantity” for everyone. Instead, everyone falls somewhere along a spectrum (except with psychoticism).

There are plenty of other theories that have come out since. But Eysenck’s research, especially in its application to the criminal world, was a huge innovation. It helped explain from a psychological-personality perspective why people commit crimes.