Because of the pervasiveness of online masks, people often question the truthfulness of online self-presentations, especially overly positive or flattering ones. Warranting theory (Walther & Parks, 2002) suggests that, when assessing someone’s online self-descriptions, we consider the warranting value of the information presented—that is, the degree to which the information is supported by other people and outside evidence (Walther, Van Der Heide, Hamel, & Schulman, 2008). Information that was obviously crafted by the person, that isn’t supported by others, and that can’t be verified offline has low warranting value, and most people wouldn’t trust it. Information that’s created or supported by others and that can be readily verified through alternative sources on- and offline has high warranting value, and consequently is perceived as valid. So, for example, news about a professional accomplishment that you post on your Facebook page will have low warranting value. But if the same information is also featured on your employer’s Web site, its warranting value will increase (Walther et al., 2008).

Not surprisingly, the warranting value of online self-descriptions plummets when they are directly contradicted by others. Imagine that Jane, a student in your communication class, friends you on Facebook. Though you don’t know her especially well, you accept and, later, check out her page. In the content that Jane has provided, she presents herself as quiet, thoughtful, and reserved. But messages from her friends on her Facebook wall contradict this, saying things like: “You were a MANIAC last night!” and “U R A wild child!” Based on this information, you’ll likely disregard Jane’s online self-presentation and judge her instead as sociable and outgoing, perhaps even “crazy” and “wild.”

Research shows that when friends, family members, coworkers, or romantic partners post information on your page, their messages shape others’ perceptions of you more powerfully than your own postings do—especially when their postings contradict your self-description (Walther et al., 2008). This holds true not just for personality characteristics such as extraversion (how “outgoing” you are), but also physical attractiveness. One study of Facebook profiles found that when friends posted things like “If only I was as hot as you” or (alternatively) “Don’t pay any attention to those jerks at the bar last night; beauty is on the inside,” such comments influenced others’ perceptions of the person’s attractiveness more than the person’s own description of his or her physical appeal (Walther et al., 2008).