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How to Know When an Online Liar Is Lying

Four clues to deciphering the language of online lying.

Whether you're rebounding from a broken relationship, moving to a new geographic area, or trying to expand your circle of friends and lovers, you can benefit from the wide opportunities that internet dating sites provide. However, these sites also can trap the novice unless you know how to spot an online liar. Unlike in-person interactions, you can't rely on nonverbal cues such as micro-expressions of fear, sideways glances, or nervous fidgeting.

Though internet lie detection may seem to be a daunting task, it's not an impossible one. Once you understand the language of the online liar, you may actually prefer the cues you can read on the screen rather than the cues you read on someone's face.

Communication professors Catalina Toma (University of Wisconsin-Madison) and Jeffrey Hancock (Cornell University) decided to use their analytic tools to detect the language patterns shown by online liars (Tona & Hancock, in press).  They conducted in-person interviews of 80 online dating service users who previously completed online profiles.  Participants rated the accuracy of their own self-descriptions, a process that could be prone not so much to outright lying, but at the least, to self-deception or exaggeration. After all, we don't always want to admit the truth about ourselves to ourselves. To supplement the self-ratings, the researchers also calculated an objective deception index comparing what participants said about their physical attributes (height, weight, age) with their measured attributes.  Photos presented yet another challenge. A group of undergraduates compared the online photos to photos taken in the lab to determine how accurate they were.

The deception index provided, in the words of the scientific method, the "dependent variable." In other words, building an index showing how far people's online profiles deviated from the reality of their true attributes, allowed the researchers to move on to figure out how to predict the extent to which online liars lie.

To tackle this prediction problem, Toma and Hancock enlisted the help of a computerized linguistic program.  The program analyzed the open-ended self-descriptions that participants included in their profiles. By crunching the numbers and types of words the online daters produced, the computer found these 3 revealing cues to lying.

Wouldn't it be nice if a mouse could serve as a lie detector?

First, online liars tended to avoid the topics about which they lied in their profiles. If they lied about their weight, they avoided using food-related words. If their photos lied about their appearance, they wrote more in their self-descriptions about work and other achievements to deflect attention away from the lies they produced about their looks. Second, liars tended to use fewer words in general. The less said, the less likely they are to be caught in a lie. Third, liars stayed away from expressing negative emotions. They wanted to exude a positive image, and that meant leaving out anything that could be interpreted as a downer.

The results of the computer analyses fit a theory known as Interpersonal Deception Theory, which predicts that liars use communication strategically to accomplish their goals.

These are great clues, then, but what if you don't have a computer that can analyze what you're reading on your computer? In other words, can people detect lying in online profiles? It would be nice if we could but, unfortunately, the human mind is more easily swayed.  We are subject to what deception researchers call the "truth bias." Most of us normally assume that other people are honest. These tendencies came out in the next phase of the study.

Looking at actual online readers, Toma and Hancock next recruited a sample of 62 undergraduates to read some of the self-descriptions the computer had already analyzed. As it turned out, the human raters were no better than chance in picking out the online deceivers.  What's more, they based their judgments solely on the length of the self-descriptions. The longer the self-description, the more truthful it seemed to the raters. Other than correctly assessing length as a predictor of truthfulness, however, humans were far worse than computers at sniffing out the liars. Humans tend to use clues such as pronouns: talking about "we" evokes more trust than talking about "you."  These aren't as relevant as the cues that computers picked up on thatseparate truthful people from  liars but they do provide evidence of a fourth clue to online lying.

If you're going to improve your online vetting skills, you're going to have to swap your human detection skills for those of the computer. These four relatively simple steps can help you learn to decipher people's online profiles:

1. Longer is better. An internet profile rich in self-description is likely to be more truthful. Liars may be afraid of getting caught in their own traps. The more detailed a person's story, the more likely it contains accurate self-depictions.

2. Look for consistency. When people describe themselves in one part of an online profile, they should be able to provide back-up evidence somewhere else that confirms it. Don't just read an online self-description from top to bottom. Go back and double check within the profile to make sure it all fits together. You could also, if you are seriously interested in pursuing a relationship with this person, resort to a Google search.

3. Recognize that liars avoid negative emotions. The person strying to sway you will try to avoid negative associations. The liar will want you to feel warm and fuzzy, not uncomfortable: "It's all good." An unrealistically positive image may be just that—unrealistic.

4. Watch out for the "we's." Avoid being drawn into the liar's web of deception that puts you and a stranger on a par. An unusually high number of first-person plural pronouns may signify a profile that is intended to make you feel emotionally close to the writer but not one that is particularly honest.

The truth bias may operate far more in online dating situations than in other everyday situations in life. If we like someone's photo (which, remember, is unlikely to be accurate), we're willing to suspend disbelief. However, the online world has plenty of traps set by people who do not have your best interests at  heart. Learn to let your head rule your heart, and your online experiences can be far more fulfilling.

Follow me on Twitter @swhitbo for daily updates on psychology, health, and aging and please check out my website, where you can read this week's Weekly Focus to get additional information, self-tests, and psychology-related links.

Copyright 2011 Susan Krauss Whitbourne, Ph.D.


Toma, C. & Hancock, C. (in press). What lies beneath: The linguistic traces of deception in online dating profiles. To appear in the Journal of Communication.  (I wish to thank the authors for sending me a pre-publication copy of the article).

Readers may also wish to follow the landmark work of Dr. Bella DePaulo, an international authority on both lying and the single experience.