Actually, by the time most kids sign up for Facebook, any narcissistic traits they might develop have already taken root.
"There is a significant amount of psychological research that shows that one's personality is fairly well-established by age 7," Bergman said. "With Facebook policy not allowing youth under age 13 to register and recent research showing that 85 percent of SNS users are over the age of 18, the personality traits of typical users are fairly well-ingrained by the time they get on a SNS."
But if Facebook hasn't fueled this generational spike in narcissism, what has?
Bergman acknowledges that unraveling the cause of millennial narcissism is complicated, but he has a hunch that it has more to do with offline interactions with parents and educators than online networking.
"Parents have coddled and overprotected their children more over the generations and have taught them, intentionally or not, to expect special treatment just for being them," Bergman said. "This, in combination with the ‘self-esteem' movement in the schools, has likely resulted in increased narcissistic tendencies in our youth."
Young narcissists do, however, have different motivations for primping their online profiles.
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Rather than keeping in touch and interacting with folks, millennial narcissists are more driven to acquire as many friends as possible and use their carefully crafted profiles to impress.
"Narcissists use Facebook and other social networking sites because they believe others are interested in what they're doing, and they want others to know what they're doing," said Laura E. Buffardi, a postdoctoral researcher at the Universidad de Deusto in Bilbao, Spain, who studies narcissism and social networking.
Narcissists' profiles tend to feature more self-promoting profile photos and first-person singular pronouns in their "About Me" sections.
And not surprisingly, that narcissistic quest for Facebook popularity can end up sullying millennials' social media image in the end.
"Some research actually indicates that there's a curvilinear relationship between number of friends and positive outcomes, such as social attractiveness and social support," Buffardi said. "That is to say, up to a point, having more friends has benefits, but after a certain large number - research indicates around 600 - these benefits actually decrease."
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