Narcissistic Personality Disorder: Nature or Nurture?

Narcissistic Personality Disorder: Nature or Nurture?

Today’s question is what causes narcissistic personality disorder (NPD)? When we talk about causation in psychology, we use the word aetiology, so if a factor is ideological to NPD, that means we believe there’s some causal component.

When we consider narcissism, it’s crucial to understand that narcissistic characteristics are part of normal human development. So, for example, we would expect to see narcissistic characteristics in childhood and adolescence.

I’m going to review NPD symptoms, and then we’ll get to the possible ideological factors. So with NPD, we see:

  • A grandiose sense of self-importance
  • Fantasies of unlimited power and success
  • Feeling special or unique
  • Needing excessive admiration
  • A sense of entitlement
  • Exploitive behaviour in relationships
  • A lack of empathy or reduced ability to experience empathy
  • Envy
  • Being perceived as arrogant or engaging in arrogant behaviour

Not all of these symptoms are required for a diagnosis of NPD, and not all these symptoms would be considered a normal part of development. Still, versions of these symptoms and characteristics would be seen throughout development, childhood and adolescence.

So when we talk about aetiology, it’s first essential to understand that we don’t really know what causes any personality disorder. We have a lot of theories, and the evidence aligns with some of those theories reasonably well in the case of some mental health disorders and not as well with others.

One of the problems with narcissistic personality disorder is that there’s no clear definition of the condition. Now the DSM has a clear definition, but not everyone who conducts research on the causality of narcissistic characteristics agrees with that definition.

So there are essentially three popular theories about the causality of NPD.


The first is that it’s inherited; we call this heritability. When we look at mental health disorders, it’s not unusual that a percent of the contribution is thought of as genetic in many cases. We look at this as heritability versus environment, the amount of variance that genetics can explain versus the amount of variance that stressors can explain for the environment.

So when we look at NPD, the heritability is somewhere between 40% and 65%, so there’s a reasonably significant contribution from genetics to the development of NPD.

Structural Differences in the Brain

The next area is the structural changes or differences in the brain. Many studies have been done using equipment to scan the brains of individuals with NPD and people who don’t have NPD and look at the differences that might be there.

One of the problems with these studies is that there have been some structural differences identified, but it’s not consistent across all presentations of NPD. The differences that have been identified are related to areas of the brain responsible for social behaviour and emotional regulation, which would be consistent with our understanding of what we see in NPD in terms of the symptom criteria.


The last area of potential aetiology is the environment, and a lot of focus with NPD is on experiences during childhood. We see specific characteristics more associated with NPD than others, so whenever we talk about ideological factors and mental health disorders, we’re often talking about associations that we see, just like with heritability and brain structure. It doesn’t mean that genetics or the brain structure causes NPD. It just means there’s an association, and the same is true with environmental factors, including the experiences in early childhood.

However, some of the factors that seem to have an association with an increased risk of developing narcissistic personality disorder would be a situation where a child receives excessive praise and excessive criticism, so there’s not really much area in the middle. We also see lack of parental empathy as a factor, recognition for abilities or appearance instead of other characteristics and an emphasis on status or achieving success, meaning an emphasis created by the parents imposed on the child.

Other potential ideological factors include emotional abuse and neglect. We see these for many personality disorders and several mental health disorders that are not personality disorders, so emotional abuse and neglect seem to cause a lot of mental health difficulties later in life. We also see with NPD, parents repeatedly over evaluating the characteristics of a child without an emphasis on balance and without looking at some other areas of improvement.

There’s often inconsistent parenting, authoritarian parenting and parents who don’t supervise the child regularly, so a lack of supervision. Another theory with NPD is that it’s caused by learned behaviour, which is consistent with the genetic information.

So that could explain the high heritability in addition to genetics could be that really what’s happening is the parents of individuals with NPD would be more likely to have narcissistic characteristics. The children are simply learning that it’s a learned behaviour.

So they grow up learning to be arrogant, lack empathy and require excessive admiration and the other symptoms we see of NPD. Therefore it’s essential when we look at studies that examine heritability that we make sure in that research methodology that the research is accounting for the possibility of learned behaviour.

We also notice as a potential illogical factor that parents of individuals with NPD have a higher probability of being unable to regulate emotions. So when those individuals grew up, their parents really couldn’t identify and control emotions and teach the child to be aware of their own emotions.

Now, this is consistent with what we see in NPD. Many individuals who have suffered from NPD lack emotional awareness, not just empathy, but they also lack emotional awareness in general.

Individuals with NPD often find themselves looking to other people to help identify emotions for them. Again, this is relatively consistent with the possible ideological factor of having parents who didn’t do a good job identifying and regulating emotions. That whole emotional awareness component really isn’t well-developed often in individuals with NPD.

So those are some of the possible illogical factors for a narcissistic personality disorder. NPD is a destructive disorder; it comes with a lot of pain and suffering not just from the symptom criteria but also from comorbidity. We see a lot of other disorders that co-occur with NPD, most notably depression, anxiety and substance abuse disorders, so mental health clinicians most definitely need to continue to work to identify the ideological factors of this disorder.

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