Since Narcissus fell in love with his own reflection, narcissism has been tied to sex. Put narcissists in front of the Internet, and new research shows that they satisfy their preoccupation with sex by watching more porn.

Though people often use narcissism as a casual term, it has a formal psychological definition. Narcissists are entitled, self-focused and egotistical, lacking in empathy, and pleasure seeking, and they use others for personal gain. At a certain point, narcissism enters the realm of a personality disorder, but we all may have narcissistic personality traits at different levels.

Psychologists have shown that narcissists tend to be more sexual. They have a preoccupation with sex, more sex partners, and a need for sexual stimulation. So, some researchers theorized, narcissists’ strong sexual motivations might mean that they watch more online porn than non-narcissists do.

The results of the study were published this month in the Journal of Sex and Marital Therapy The researchers measured people’s narcissism and found out about their porn-watching habits. The study included more than 250 people with an extensive range of ages (18-61), and the majority of whom were women (63 percent). Each person took a series of widely accepted personality tests designed to measure different narcissistic personality traits, and they reported on their Internet porn viewing habits.

Most of the subjects—almost 80 percent—reported that they had watched porn online at some point, and 44 percent said they “currently” viewed it. (One can hope they were not actually watching porn while taking the surveys.) Interesting tidbits: People who were active online porn viewers averaged 85 minutes per week. Men tended to watch more than women.

The analysis showed a significant relationship between porn viewing and narcissism. Using values both the Narcissistic Personality Inventory (a standard and commonly used measure of narcissism) and the Index of Sexual Narcissism, researchers found that narcissistic traits were strongly related to porn viewing.

When people were divided into groups of those who had watched porn and those who had never watched it, the porn watchers had significantly higher narcissism scores. “Current” porn viewers also had much higher narcissism scores than their counterparts who had only watched it in the past.

This relationship scaled, too. The more often people watched pornography online, the more narcissistic they tended to be.

That’s interesting, but does it matter? After all, it’s unlikely that PornHub can track down narcissists for marketing purposes. The research does not show any causal relationships either way; we don’t know that narcissism makes people watch more porn or that watching more porn makes people narcissistic. But the authors offer a possible implication of their results: watching porn could make people more narcissistic.

Thomas Kasper of the University of Houston – Clear Lake, one of the authors of the article, explains that theory. At the core is the fact that narcissists are fundamentally selfish. He reasons that watching more pornography may change our view of sexual partners.“Pornography is limited to just pleasure or pleasure for ourselves. When it is limited to these conditions, it feeds our narcissism. Individuals may begin to view others [as] less whole and use them for their own needs/wants/desires.”

Certainly, pornography objectifies women (and sometimes men) and minimizes the emotional components of sex. It is interesting to contemplate if that watching it might, in turn, make us more selfish as human beings.

This wouldn’t be a total surprise given what we know about narcissism and Internet usage. Research published earlier this year found connections between social media usage and narcissism. Some activities, like choosing and posting profile photos the user finds especially attractive, are linked with higher narcissism levels, while many interactive activities like chatting are linked with greater empathy and lower narcissism.

And narcissists often embrace social media. They have more friends, post more, and are more provocative to get attention. And while we know that narcissism leads to more social media use, there are questions about whether social media increases narcissism. These are the same questions about whether online pornography increases narcissism.

Taken together, this raises interesting questions about the relationship among narcissism (and other personality traits), social media, online pornography viewing, and Internet use more broadly. Our personalities certainly influence what we do online, but what if our online behavior influences and changes our personalities?