Turns out you can size up personality just by looking at a person’s Facebook profile. While that may not seem like a big deal, it is providing fodder for academics who are trying to predict temperament based on the things we post online.

If such predictions prove accurate, employers may have good reason to poke around our Facebook pages to figure out how we would get along with others at the office. And Pentagon officials want to use personality assessments to make better decisions on and off the battlefield.

A recent study by researchers at the University of Maryland predicted a person’s score on a personality test to within 10 percentage points by using words posted on Facebook.

“Lots of organizations make their employees take personality tests,” said Jennifer Golbeck, an assistant professor of computer science and information studies at the University of Maryland. “If you can guess someone’s personality pretty well on the Web, you don’t need them to take the test.”

Golbeck and her colleagues at the university’s Human-Computer Interaction Lab — where she’s the co-director — surveyed the public profiles of nearly 300 Facebook users this year. They looked at users’ descriptions of their favorite activities, TV shows, movies, music, books, quotes and membership in political organizations. They also looked at Facebook’s public “About Me” and “blurb” sections.

The 300 participants then took a standard psychological exam that measures the “big five” personality traits: openness to experience, conscientiousness, extroversion, agreeableness and neuroticism. (People who don’t post very much on Facebook aren’t good candidates for this kind of study.)

People who tested as extroverts on the personality test tended to have more Facebook friends, but their networks were more sparse than those of neurotics, meaning that their friends were less likely to know one another than were the friends of other Facebook users. People who tested as neurotic had more “dense” networks of people who know one another and share similar interests.

The researchers also found that people with long last names tended to be have more neurotic traits, perhaps because “a lifetime of having one’s long last name misspelled may lead to a person expressing more anxiety and quickness to anger,” according to the study. People who tested high on the neurotic scale also tended to use a lot of anxiety-associated words, such as “worried,” “fearful” and “nervous,” on their Facebook posts.

They also use words describing ingestion: “pizza,” “dish, “eat.”

Golbeck says she can’t explain that last correlation. “You’d have to get a psychologist or psychiatrist on that one,” she said. “It could be that people that are neurotic talk more about what they are eating. It could be a deep correlation that we can’t understand on the surface.”

In touch, or isolated?

Golbeck says that gauging a person’s personality is important to anticipating how well they will get along with others in school or a job.

But some critics say that you can’t really use social media to figure out human behavior.

Sherry Turkle, a professor of the social studies of science and technology at the Massachusetts Institute of Technology, says that people who spend a lot of time online, on Facebook and other sites, actually may be more isolated from the world than in touch with it. Trying to understand someone’s “real” personality from their daily postings on Facebook and Twitter misses too much information, according to Turkle, author of “Alone Together: Why We Expect More From Technology and Less From Each Other.”

“If we are taking what people do on Facebook as a measure of their sociability, does it measure how well they can apologize and say they are sorry?” Turkle asked. “Does it measure their emotional strength or weakness? It isn’t capturing their voice, their facial expressions, the visual cues and how you feel with this person next to you in the room.”

Turkle, a clinical psychologist, interviewed hundreds of people for her book. Many of them feel they have to “perform” on social media sites to act cooler, more interesting or funnier than they are in real life, she says.

“There is so much fear of missing out,” Turkle said. “You are there doing your little things every day, and everyone else is skiing at Gstaad. People don’t like to write that their dog died.”

Sorting it out

But Golbeck’s approach to social media and personality profiling does have its supporters.

People can exaggerate aspects of their personality when using social media, said Cliff Lampe, a professor of media studies at Michigan State University. “It’s like any tool. We usually sort it out over time.”

Lampe admits that his undergraduate students have a bit too much trust in what they learn or whom they meet online, more so than older people who use social media. “Maybe older people have more experience and been burned a few more times,” he notes.

On the other hand, his students are much savvier about understanding the privacy settings that keep strangers (or prospective employers) from seeing those embarrassing bar-hopping photos.

Figuring out whom and what we can trust online is becoming more important as social media networks keep getting bigger. Facebook now says it has 600 million active users worldwide (nearly 150 million in the United States); Twitter claims nearly 200 million.

Golbeck is getting attention from both big social media companies and the military. The Army Research Laboratory is interested in predicting how soldiers will get along in the field — so-called “unit cohesion” — and is funding her studies of personality. Another Defense Deptartment unit, the National Geospatial-Intelligence Agency, is funding Golbeck’s development of a battlefield board game — and eventually a computer-based game — that involves trust and how soldiers can navigate across enemy terrain. Social media firms want her to help them profile their users.

And as good as Facebook is in revealing personality, Twitter is even better, says Golbeck.

“I think of Twitter as the lounge of your dorm,” Golbeck said. “You walk in there, there are lots of people there and you have stuff to say and you tell them. Check this out, or I just went to this great place for lunch. What Twitter gives you is this insight about what the world says in this context, what people are happy or sad about.”

Golbeck says that by analyzing the words people use on Twitter, and the back-and-forth between followers and followees, she can make a good estimate of people’s personality — even better than her recent study of Facebook profiles.

As for herself, Golbeck has two Twitter accounts, one for friends (mostly fellow Caps fans) and one for professional colleagues. She also keeps a tight rein on her Facebook friends (about 120). She believes Facebook and Twitter will continue to evolve, and users will get more savvy about how they use social media and who gets to look at our private lives. Friends’ lists are getting smaller as users remove the random people they don’t know very well.

“I can already see it in my students,” she said. “It’s no longer a race to connect to the most people. It’s about sharing important things with a smaller group of people,” she said.

Niiler is a freelance writer in Chevy Chase.