Is narcissistic personality disorder (NPD) hereditary?

In most of the cases that the researchers and mental health professionals studied, they studied different aspects of narcissism and factors contributing to its origin. These are some factors: biological vulnerability, social interactions with the parents and teachers, upbringing, and many other psychological factors that involve temperament. The extensive studies suggest that genes for narcissism is present in everybody and it varies in amount. Everybody love himself and care for himself. There are deep studies that studies specifically at whether narcissism is genetic or it is originated after the birth. although, most of the causes of NPD are Early childhood trauma, suffering, lack of love and care during upbringing and exploitation.

Researchers use two different methods to study genetics of personality, these methods include: identical twin studies method and examination of the human genome method. Twin studies method examines identical twins that were separated at the time of birth and raised in different conditions in different households.Identical twins have identical genes and therefore, any similarities in their personality traits may be because of Genetics. Researches have suggested that Identical twins raised in different conditions, separately have more personality traits vis-a-vis fraternal twins, who do not share identical genes.

 

Scientists try to correlate the existence of specific gene variations with personality disorders. According to a study in a 2007, issue of the "International Journal of Neuropsycho-pharmacology", a particular gene called Tryptophan hydroxylase-2 may be involved in the occurrence of some specific personality disorders, including NPD. Tryptophan hydroxylase-2 helps in regulating the production of an important brain chemical, responsible for mood regulation, called Serotonin.

Livesley W.J, in his research "Genetic and environmental contributions to dimensions of personality disorder." concluded, in agreement with other researches and studies, that narcissism as measured by a standardized test was a common inherited trait. The study were done on 175 twin pair volunteers (ninety were identical, eighty-five fraternal) drawn from the general population. Each twin had to answer a questionnaire that aimed at assessing eighteen characteristics of personality disorder. The authors assessed and studied each characteristic by standard methods, and provided an estimate of the comparative contributions of genetic and environmental causation.

Of the eighteen personality characteristics that were assessed during the research, It was really shocking to get the results. The narcissism have the highest inheritance, this trait in the identical twins was notably influenced by genetics. Of the remaining seventeen characteristics, only four of them were found to be statistically significant: callousness, identity problems, oppositional defiant disorder and social avoidance.

Advancement in science and technology, made research much easy. Technical advancement such as, Brain imaging have proved that the brains of the people with Borderline Personality Disorder (BPD) and Anti-social Personality Disorder (APD), both of them are in the same group of personality disorders as NPD, are not performing properly. The activity levels in the brains of persons with BPD and APD are abnormal. Researches and studies having the “cluster B” personality disorders, have confirmed notable physiological brain dysfunction in two of the four cluster B disorders. What is the cause of the brain not functioning properly is not completely understood.

There is very less progress in the studies and researches of NPD, as most of the narcissists don't admit and feel to have any problems and they don't visit a doctor or therapist unless pressurized by family or friends.

Some other researches were conducted on persons with BPD has detected this disorder in the offspring at a rate of  68%. In simple words, approx. two thirds of the children of the parents those diagnosed with the BPD have BPD themselves. A review of certain literature suggests that narcissism is hereditary and inheritable, that many narcissists have had a narcissistic father or mother. But does that prove it is hereditary or a learnt behavior?

The scientific researches on NPD and other Cluster B disorders expatiate and results are more reliable, it seems that there are greater chances of genetics may play a significant role to some degree.

Interpretation

There are many theories about the occurrence and the causes of Narcissistic personality disorder. Some researchers and theorists suggest that narcissism as a primary genetic, but many psychoanalyst and health professionals disagree and believe narcissism to be rooted in childhood of a person. There are very less studies done to date on the causes of narcissism, but some geneticists have hinted that a high-frequency recessive gene as a genetic clarification for the personality trait and for the more severe form of NPD.

Currently, there is no proper cure for NPD but the talk therapy, counseling and some medication may work with proper consultation to a professional. The most common piece of advice that the therapist or psychoanalyst give to their clients who are involved with a narcissist is the same, I.e. No contact or at least limit the contact with narcissists as much as they can. People with NPD cannot change their behavior.

On a personal note, I would suggest, that the idea of NPD being hereditary is probably has been influenced by the fact that the narcissistic parents often raise children having narcissistic traits. Though, it may seem that the NPD is mostly inherited but it the fact can't be denied that the poor upbringing and lack of love and affection during childhood contribute a lot to the raising a child as a Narcissist.