Narcissistic Personality Disorder or NPD is a illness defined by the oxford dictionary as a personality disorder characterized by an exaggerated sense of self-importance, a need for admiration, and a lack of empathy for other people. The name comes from the ancient greek fable of Narcissus. He was a very proud man that was led to a pool by another character Nemesis. Narcissus allured by his self perceived beauty in the reflection managed to drown himself. People are born with different predispositions to NPD due to structural abnormalities in the brain such as thinner areas of gray matter in the left anterior insula in the cerebral cortex. This was proved to have an impact on a persons ability to empathise although it isn't solely responsible .
I think that nurture is way more effective in causing narcissistic traits rather than nature. To overpraise a child is planting the seed that they are unique or above the general population . Nowadays parents congratulate kids for doing basic acts such as doing chores rather than to show respect to them. Praise is a validation that teaches young people to hunt for more validation due to dopamine release. To respect them is to let them know they are an asset that will know their value without overinflating their ego. The key to stopping this is to try replace a reward system to one of realization of the acts, causes and consequences. Im not a nazi that thinks kids shouldn't be allowed eat sweets or get birthday presents but an emphasis should be put on generating a curiosity of what is going on rather than a personal reward for complying. Another cause of Narcissism is due to undervaluation. Being constantly told a thing about yourself by external forces will imprint and be internalised. A childs brain is very malleable and if it is constantly being fed depreciating experiences then it will expect nothing more. This gives rise to low self esteem and a self loathing. This sounds very contrary to being in love with yourself like the greek myth, but the narcissism arises as a coping mechanism to deal with the inner psyche of self hatred.
One of the questions that people will wonder is why does a narcissist hate me or try undervalue me? The answer is that it is in no way whatsoever personal. I once told a story about a fat girl joking about her weight to a person who was also slightly chubby without me realizing my passive aggressiveness until halfway through the story. It isnt a conscious dislike for people but more a lack of value for them as people of equal value which in turn limits human connection and awareness of them.It isn't healthy to be close friends with a grandiose narc or vulnerable one, one will not listen or care for your wants. the other isnt capable and is only there to play the victim and spectacle without giving anything of substance back to the relationship.
The majority of narcs will go undiagnosed or without realizing as to be a narcissist is to embrace your own values and opinion over others no matter how irrational. This occurs in humans but a narcissists "gut feeling" will not be shot down . If you told one they had narcissistic traits they wouldn't listen. Paying no attention to what others say is essential to the narcissist. Words and feelings of others cannot make it through the stubborn defenses set up to block out the negatives. It is the adult equivalent of a child screaming LALALALALALAICANTHEARYOULALAL . emotional underdevelopment is essential to this disorder. The only reason i became aware of my insufferableness was by stumbling onto a quora article which described narcissism and i felt like i related but only very loosely. Extreme sufferers cannot be helped as they will never realize they have a problem.
"Do-Gooder" narcissists will not swallow that bitter realisation. They are easy to recognise as they will not be asked to help and will usually not be needed. If denied general approval to help then one will become angry further proving their issue is with how they are viewed rather than the issue at hand.
integrity is being emotionally and overtly honest enough to recognise what you want from a situation and to not convince yourself that you had less selfish motives. Narcissists struggle with being covertly good but will make a song and dance of their good deeds in public in order to gain the levels of attention they were either overindulged in as a child or never given at all. selfless illusion> selfish reality
Sources:Thelittleshamanhealing youtubechannel
https://www.livescience.com/37684-narcissistic-personality-disorder-brain-structure.html
https://www.recoveryranch.com/mental-health/narcissistic-personality-disorder-causes-nature-vs-nurture/