Deception refers to the act—big or small, cruel or kind—of encouraging people to believe information that is not true. Lying is a common form of deception—stating something known to be untrue with the intent to deceive.
While most people are generally honest, even those who subscribe to honesty engage in deception sometimes. Studies show that the average person lies several times a day. Some of those lies are big (“I’ve never cheated on you!”) but more often, they are little white lies (“That dress looks fine”) deployed to avoid uncomfortable situations or spare someone's feelings.
Trust is the bedrock of social life at all levels, from romance and parenting to national government. Deception always undermines it. Because truth is so essential to the human enterprise, which relies on a shared view of reality, the default assumption most people have is that others are truthful in their communications and dealings. Most cultures have powerful social sanctions against lying.
There are sins of commission and sins of omission; omitting information and concealing the truth are considered lies when they are done with an intent to deceive. In addition to statements that are false, deception encompasses statements that misrepresent or distort facts as well as the withholding of information. People can lie through outright statements or by strategic silence.
People may deliberately create false information or fabricate a story. But most often, sheer invention is not the soul of lying. Rather, people deceive by omitting information, denying the truth, or exaggerating information. Or they might agree with others when in fact they don’t, in order to preserve a relationship. Self-serving lies, on the other hand, help liars get what they want, make them look better, or spare them blame or embarrassment.
Deception isn’t always an outward-facing act. There are also the lies people tell themselves, for reasons ranging from maintenance of self-esteem to serious delusions beyond their control. While lying to oneself is generally perceived as harmful, some experts argue that certain kinds of self-deception—like believing one can accomplish a difficult goal even if evidence exists to the contrary—can have a positive effect on overall well-being.
Gaslighting is a pernicious form of manipulation in which someone is deliberately told false information with an intent to harm—specifically to undermine their sense of reality. Lies are used as weapons in an effort by one person to exert control over another. The tactic is commonly deployed by abusers, narcissists, cult leaders, and dictators.
Delusions are an extreme, pathological form of self-deception. They are false beliefs that contradict reality but which a person is convinced are true—and may go to great lengths to convince others are true. Delusions are typically a symptom of impaired reality perception, common to mental disorders such as mania and psychosis.
Researchers have long searched for ways to definitively detect when someone is lying. They know that some people are better at lying than others; their visual and verbal cues are in sync with what they are saying. But studies consistently show that most people are terrible at detecting deception, performing no better than chance. There’s evidence that many people have inaccurate beliefs about signals of lying—for example, that fidgeting is always a giveaway.
Many experts propose that liars reveal themselves in "tells," major and minor changes in body language or facial expressions. But observable signs of lying can be unreliable. Researchers do find that some people lie more than others. Studies show that children under two never lie and that lying peaks in adolescence, when social relationships take on heightened importance.
Most people are not aware of the ways they fool themselves. But psychologist have identified many signals of self-deception. Outsize emotional reactions to present situations, behavior that is out of step with who you claim or aim to be can be indicators that we believe things about ourselves that are false or fail to believe things that are true.
There is a longstanding belief that the eyes are a window to the truth, that liars are “shifty” and inadvertently signal their deception by averting their gaze or altogether avoiding looking a conversation partner in the eye. But science gives the lie to that belief. In fact, researchers have found that people make more eye contact when lying than when telling the truth.
Covering a neck with a hand, raising the inside edge of a foot, compressing the lips—all are signs of tension that has been linked to lying. There is a widespread belief that the body and face are always honest and provides reliable clues to lying—often called “tells”—if you know what to look for. But experts now believe that there a no single behavior indicative of deception, although such so-called nonverbals should be seen as alerts to possibly concealed or suspicious information that requires further probing.
Researchers find that language and speech can offer possible but not definitive clues to deception. In analyses of text messages, liars tend to ramble more, present few verifiable facts, and seem less certain of the facts. In speech, overuse of little utterances like um, ah, you know, right?, I mean can be clues to the cognitive load involved in lying.
One of the best-known methods, the polygraph test, is based on the theory that lying alters normal psychophysiological patterns that can be detected by sensitive machinery. Although popular in crime dramas and movies, the test has long been controversial, with no evidence that there are definitive fluctuations in physiology. Evidence suggests that those with certain psychiatric disorders, such as antisocial personality disorder, cannot be accurately measured by polygraph or other common lie-detection methods.
According to one expert, lies are like wishes—often, what is said are things people wish were true. A large body of research identifies three major reasons why people lie: to get something they want, so-called instrumental reasons; to protect or promote themselves; and to harm others. Avoiding punishment may be the main motivation for both children and adults.
While everyone lies a little, it appears that only a small percentage of people do most of the lying. There’s evidence that prolific liars share the personality trait of Machiavellianism: They are manipulative and exploitative of others; the trait is closely related to psychopathy.
Intentions matter when it comes to behavior—it’s often a deciding factor in the law—and there are times when lies can help others or shield them from harm. Sometimes lies are told to prevent difficult conversations, such as those involving critical feedback, and they may appear protective. But they can ultimately disadvantage the recipient by depriving him or her of useful information that can promote positive change.
Experts differ on the topic. Some believe that even white lies, told with the aim of protecting others or smoothing social relationships, are damaging because they deny people the experience of reality that could be used to improve their lives. Lies are damaging to relationships because they block intimacy. Lies are considered harmful because they destroy trust—the bedrock of society—the belief that others are dependable and intend no harm.
Lies that knowingly inflict harm are widely regarded as immoral. But sometimes lying is done for good purposes. People may lie to protect others—so-called altruistic lies, such as when a doctor tells a family that their father died a peaceful death when he in fact did not. Some lies are told to help people achieve their goals, such as when a spouse tells a dieting partner that there are no sweets in the house. Many ethicists believe that lies that committed to benefit others should be seen as justified, and that a certain amount of deception may be necessary for maintaining a healthy, functioning society.
Pathological, or compulsive, liars tell lies about themselves and others for no discernible purpose, and they lie even when their claims are obviously false. Sometimes their behavior is an indicator of a personality disorder such as psychopathy. Researchers believe that such people may lie as a way of maintaining control or to avoid disappointing others. Or their lies may be a form of wishful thinking.
Although the term “fake news” is relatively recent, the dissemination of deliberately false information, or disinformation, to manipulate public attitudes is not new. Nazi propaganda spread anti-Semitic lies to further Hitler’s goals of exterminating the Jews. The internet enables the creation and spread of fake news, including doctored videos, at high speed and puts the burden of verification of information on the reader. Experts advise people to generally exercise skepticism, especially at information that is surprising, and to always check the reputation of news sources.