Bangalore:Are you on Facebook? Then, make sure you post a nice, impressive photograph, as users on the social networking sites appear to form judgements on profiles without even reading words, researchers say. The researchers at the Ohio State University in the US also found that people pay closer attention to information that could be viewed as negative or not normal on such sites. It seems a profile photo on Facebook tells viewers all they need to know to form an impression of a person and no words are really necessary, they said. In one experiment, the researches found college students who viewed a Facebook photo of a fellow student having fun with friends rated that person as extroverted -- even if his profile said he was "not a big people-person". The only exception is when a photo is out of the ordinary or shows someone in a negative light. In that case, people do use profile text to help interpret what kind of person is shown in the profile, they said. "Photos seem to be the primary way we make impressions of people on social networking sites," lead author Brandon Van Der Heide was quoted as saying by the Daily Mail. "People will accept a positive photo of you as showing how you really are. But if the photo is odd or negative in any way, people want to find out more before forming an impression," he said. For their study, published in Journal of Communication, the researchers recruited 195 college students and made them view mock Facebook profiles of a person that included a photo and a written "about me" statement. Participants were asked to rate how extroverted they thought the student in the profile was, on a scale of 1 to 7 based on the photo and text. It was found the profile, which had a photo showing the person enjoying a night out with friends and a text saying he was the happiest person with a big group of friends, was rated as the most extrovert. Surprisingly, the participants also rated the person most extrovert if his profile had a extroverted photo but a text suggesting the person was an introvert