HOUSTON – Thank goodness for personality disorders. Without psychological illness, the adult internet might cease to exist.

Take narcissism, for example. Most people display at least a few narcissistic behaviors from time to time. However, as defined by the medical community, people with narcissistic personality disorder display elevated levels of selfishness, entitlement, egotism, lack of empathy and pleasure-seeking. It’s that last one that has implications for the adult entertainment industry.

A study published in the October issue of the Journal of Sex and Marital Therapy indicates people who score high on psychological tests for narcissism tend to watch more online porn that those who receive average or low scores. The converse also is true: People who watch lots of online porn tend to score high on narcissism scales.

To reach their conclusions, researchers studied more than 250 subjects ages 18-61. Sixty-three percent of participants were female. Almost 80 percent of the subjects, regardless of gender, reported they had watched porn online at least once; 44 percent they continue to be “active” online porn viewers. Active viewers averaged 85 hours of online porn watching per week, with men reporting slightly more hours per week than women.

Each of the subjects took a series of tests designed to measure various narcissistic personality traits; all of the tests are commonly used by psychological professionals.

Analysis of the data indicated a strong correlation between narcissism and porn use. Moreover, those who currently watch online porn showed more narcissistic traits than those who watched in the past but no longer do. Researchers also discovered a correlation between amount of porn watched online and narcissism scores: the more hours spent watching porn, the higher the narcissism score.

Researchers stopped short of declaring a causal relationship between narcissism and online porn in either direction, but they did conclude that watching online porn could increase a subject’s inherent narcissism by decreasing his or her regard for sexual partners.

“Pornography is limited to just pleasure or pleasure for ourselves,” explained Thomas Kasper, a researcher at the University of Houston – Clear Lake and one of the authors of the study. “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 and desires.”

To be fair, other recent studies have indicated anyone who spends a great deal of time online, particularly using social media, may be prone to narcissism. In those studies, researchers did determine narcissism leads people to seek out and interact on social media, often in maladaptive ways. However, questions remain about whether embracing social media to extremes increases narcissism.