Washington: People can accurately detect the personality traits of strangers through Facebook activity, according to a new study.
However, changes to the social media site in the past three years could be making it harder to do so, scientists said.
Researchers at The University of Kansas sampled 100 Facebook users, paralleling the demographics of the social networking site, and asked them to fill out a personality survey.
A group of coders looked at each person's Facebook activity, 53 cues in all, to see whether certain personality types were more likely to do specific activities.
The researchers then had 35 strangers spend 10 to 15 minutes on each of the Facebook users' profile pages to see if they could correctly gauge a person's personality.
The study looked at which cues correlated to personality types and whether the 35 strangers were able to correctly detect personality traits based on those cues.
The research found that extroversion was the easiest personality trait for strangers to interpret followed by agreeableness and openness.
There was just one cue that pointed to conscientiousness and none that helped detect neuroticism.
While strangers were able to correctly match certain Facebook activities with personality traits, the researchers believe new algorithms enacted by Facebook could make it harder to detect personality traits.
Since the data was collected in 2011, Facebook has changed how and when users see other people's activity, researchers said.
At the time data was collected, users saw every action - from likes to changes in personal history - their friends took.
Now, those actions can be viewed in a small box in the upper right-hand corner of the page, making the actions less apparent.
Today, the posts on Facebook's most prominent feature, the newsfeed, are based on an algorithm that takes into account how recent the post is, how many people like it or have commented on it and if the user has frequently interacted with the person making the post.
That's an important shift for judging personalities because, according to the study, an agreeable person tends to post less often, an open person is less likely to respond to other people's posts but make more political status updates, and a conscientious person agrees more often with what other people post.
So, if Facebook changes how often users see their friends' posts, users could be forming the wrong impressions of their friends, researchers said.
"If Facebook suddenly starts highlighting people you may not have regularly interacted with and promotes a lot of posts from them, you may no longer think that person is agreeable," said KU doctoral candidate Natalie Pennington.
"It may not be that they post that much, but that your feed has gotten smaller and shows a smaller subset of friends," she said.
The study will be published in the journal New Media & Society.