Narcissism, Machiavellianism, and psychopathy.

In psychology, they’re known as the “Dark Triad.” By looking at tweets, Jordan Carpenter and Daniel Preotiuc-Pietro, postdoctoral fellows in Penn’s Positive Psychology Center, have figured out how people who exhibit these behaviors act online.

The researchers started by looking at the distinguishing characteristics of each group. Narcissists have an inflated but brittle self-view, says Carpenter, and are constantly seeking admiration. Machiavellians are cynical and see other people as a means to an end. Individuals with psychopathic traits are quick to follow their own impulses, don’t look to the future, and do what they want with no sense of right or wrong.

Social media offered the research team a unique window into how people who demonstrate these behaviors think. Several thousand volunteers took an online questionnaire, rating on a scale of 1 to 5 how statements such as "I tend to expect special favors from others" described them. Of those thousands, 863 willingly provided the researchers with a Twitter handle and had a publicly accessible profile. The researchers then analyzed up to 3,200 tweets per user.

“We also downloaded their profile image and computed network statistics like number of friends, number of followers, if they tweet from mobile phones,” Preotiuc-Pietro says.

A computer algorithm the researchers built looked at how likely the use of words, phrases, and emotions—anger, joy, fear, and appreciation, for instance—related to any of the outcomes.

At the onset, they learned that psychopathic behavior in tweets took the form of anger, violence, and something called positive aggression. (Think violent news events that, to some, represent courage, freedom, patriotism, and justice.) Those with narcissistic tendencies showcased positive emotions, posting about general daily activities and, interestingly, television shows.

“Narcissists can be very charming. They’re very engaging. They’re very energetic,” Carpenter says. “This kind of positive face to the world.” 

“But they also talk about their mundane activities on Twitter, which they think others are interested in,” Preotiuc-Pietro adds. 

The researchers were unable to determine Machiavellianism traits from the tweets. Carpenter says “little behavior was related to being a Machiavellian alone,” though it could be predicted in conjunction with the other two.

For the final experiment, the researchers wanted to understand how successfully such traits could be predicted. They found that it is possible to a degree better than chance, but a larger dataset could provide more complete information. This data, however, worked well to reveal much about the people who possess such traits.  

“We know how narcissists act in relationships. We know how psychopaths act when you rip them off. We know about these face-to-face interactions,” Carpenter says. “But getting insight into how these people act in free information online can give us so much more.”