In this video from TED-Ed, author and professor of psychology W. Keith Campbell explains narcissism is more than just a combination of vanity and selfishness found in pop psychology—it’s a set of classified and researched traits, and those who possess them can often cause real damage. “When their rosy view of themselves is challenged they can become resentful and aggressive,” Campbell says. “It’s like a disease where the sufferers feel pretty good, but the people around them suffer.”

The Two Types of Narcissism

Narcissists tend to think of themselves as more intelligent, more attractive, and more important than other people, Campbell says. Psychologists formally recognize two types of narcissism: While narcissism may manifest itself differently depending on the person, in most cases “the dark side of narcissism shows up over the long term,” Campbell explains. For example, a narcissistic politician may end their careers by making an unethical decisions; while a narcissist in a romantic relationship may eventually become unfaithful. Extreme forms of narcissism are classified as a psychological disorder known as narcissistic personality disorder. According to the American Psychological Association, the traits associated with narcissistic personality disorder include:

A grandiose view of oneselfProblems with empathyA sense of entitlement, and A need for admiration or attention

“What makes these traits a true personality disorder is that they take over people’s lives and cause big problems,” Campbell says. “Imagine that instead of caring for your spouse or children, you use them as a source of attention or admiration. Or imagine that instead of seeking constructive feedback about your performance, you instead told everyone who tried to help you that they were wrong.”

The Psychology of Narcissism

The environment we grow up in can determine narcissistic tendencies. Parents who place their child on a pedestal can contribute to grandiose narcissism, while those who are too controlling can lead to vulnerable narcissism. However, Campbell notes narcissistic personality disorder cannot be diagnosed until a child has fully grown, as selfishness is often a part of normal human development. Our culture also plays a role in establishing narcissistic personalities, as societies that place greater value on individuality and self-promotion see larger numbers of narcissists. “In the US, for example, narcissism as a personality trait has been rising since the 1970s when the communal focus on the sixties gave way to the self-esteem movement and a rise in materialism,” Campbell says. While social media can provide narcissists with the ability to seek attention and self-promotion that they crave, there is no clear link between social media use and narcissistic tendencies. Studies have shown there is likely a strong genetic component to narcissism, although researchers are not certain what genes are involved. Ultimately, while it can be difficult for a person with narcissistic tendencies to work toward self-improvement, it is not impossible. “Anything that promotes honest reflection on their own behaviour and caring for others, like psychotherapy or practicing compassion toward others, can be helpful,” Campbell says.