Constellation of Narcissistic Traits by Birth-Order: Nature Vs. Nurture

Introduction: Adlerian theory suggests that birth order and the number of siblings affect a child’s behavior. So, in the present assessment, the prevalence of narcissistic traits has been compared between first-born and second born children to assess once more the aforementioned claim.

Method: Six hundreds parents, among the clienteles to a medical clinic, had been asked, randomly and sequentially, to determine that which one of the traits of the narcissistic personality disorder, according to the DSM-5’s diagnostic criteria, could be accounted as a distinguished characteristic of their first or second children.

Result: All of the narcissistic personality traits, except than one (“Is interpersonally exploitative”) were significantly more prevalent among first-borne children (p<0.05). Conjectural narcissistic personality disorder (with at least five traits) too was significantly more prevalent among the first-borne children in comparison with the second -borne children (p<0.05), which was as well significantly more prevalent in male participants of the associated group (p<0.05).

Conclusion: it seems that the first-born children show higher chance for acquiring narcissistic personality traits in comparison with the secondborne children; an outcome in support of substantial role of nurture.

Keywords: Birth order; Narcissism; Narcissistic personality traits; Narcissistic personality disorder; Personality development