In the classic 1944 film Gaslight, a husband tries to drive his wife crazy by persuading her that she’s done things she can’t remember doing, and sees things — such as flickering gaslights — that don’t exist. His goal is perfidious: He knows there are jewels hidden in the family home she’s inherited and he wants to drive her insane so that he can commit her and look for them in peace. The film is notable not only for its stars — Charles Boyer plays the husband, Gregory Anton, and Ingrid Bergman plays Paula Alquist, his wife — and its seven Academy Award nominations (and two wins), but also because it gave rise to a new word that is now commonly used to describe Gregory’s particular type of deception: gaslighting. “Gaslighting is the practice of getting others to distrust their own accurate perceptions,” says David Livingstone Smith, PhD, professor of philosophy at the University of New England in Biddeford, Maine, and author of Why We Lie: The Evolutionary Roots of Deception and the Unconscious Mind and Less Than Human: Why We Demean, Enslave, and Exterminate Others. “It’s really an undermining of their sense of reality. If you can’t trust what you see and hear and feel, what can you trust?” The net effect on the gaslighted person can be more than just temporary confusion. “It has all the same physical effects associated with psychological stress,” says Dr. Livingstone Smith. Here’s the other thing: It’s not rare. It happens all the time — on the job, in personal relationships, and in the public forum, particularly in politics. The advent of media that allows gaslighters to manipulate forms of media to sustain the deception makes it even harder to spot these days. Everyday Health sat down with Livingstone Smith to discuss this form of deception — who does it, why they do it, who is vulnerable, and how to defend yourself. Everyday Health: Since gaslighting is a form of lying, I think it’s fair to start by asking why do we lie? David Livingstone Smith: Sometimes we lie to protect ourselves from some kind of danger. Sometimes we lie to get ahead. Very often we lie because we want to be loved, so we want to project a certain image of ourselves to others to gain their approval or affection. I don’t think there’s any reason to believe that human beings have a lying module in them, or that the act of lying is somehow favored by natural selection. What evolution did was give us the psychological ability to catch on to how effective a strategy it is. It’s something that works to enhance one’s success. EH: How common is lying? DLS: Lying is a normal part of life. Plants do it. Nonhumans do it. Humans do it. My favorite nonhuman example is the mirror orchid, which gets itself pollinated by producing blossoms that mimic the appearance and scent of females of the pollinating species of wasp. Being lied to is a normal part of life. If you think you don’t lie or are not being lied to, you are lying to yourself. A lot of people don’t realize that because they don’t look seriously enough at the amount of lying they do in an average day. EH: But not all lies, like Gregory’s, are deceitful and damaging? DLS: You could say there are two different kinds of lying — deliberate lying, which is strategic and maybe rehearsed, and the unconscious automatic lying that comes naturally. You engage in a social interaction and you open your mouth and lies come out and you don’t even realize it unless you reflect on it. You go to the supermarket and the woman at the checkout, who has been on her feet for hours and is paid crap, says, “How are you?” because she’s told she has to do that. And you respond and then say, “How are you?” And she says, “I’m doing well.” But in reality, she isn’t. That’s lying. It’s tough standing on your feet all day and being badly paid. EH: You’re suggesting that truth-telling is overrated? DLS: It’s a mistake to think that, on the individual level, total truthfulness is desirable or even possible. The social lives of human beings require a measure of dishonesty. Parents routinely lie to their children — for example, about Santa Claus. And good parents teach their children to lie in socially acceptable ways; for example, by thanking people for things that they are not grateful for. So, let’s not idealize truth-telling. Life is rough; deception and self-deception make it more bearable. All that being said, there is a lot of surplus deception and self-deception around that deserves to be eliminated. What we should be concerned about is consequential surplus lying. That’s the lying that’s dangerous. EH: And gaslighting falls into that category? DLS: Yes. EH: The interesting thing is that we seem to opt in for gaslighting in some situations — like sitting through a magic show or a horror movie. DLS: Right. Why do people watch horror movies? You know it’s not real, but you’re voluntarily dipping in and pretending it’s real. You’re participating in a wonderful pretense. You know the magician isn’t really doing magic, you know a monster isn’t really going to take over your mind. EH: But when we’re gaslighted — moved to question our own perceptions without our permission — it’s different. DLS: It’s involuntary. The element of pretense isn’t there. We’re not pretending. It’s a violation of trust. We’re being harmed. EH: How is it that we can be pressed into questioning our own reality? DLS: Someone who gaslights is saying, “Trust what I say, and give priority to that over your own memory and thoughts and senses.” It can happen in a lot of ways. But there are a few things that are key. One is that the gaslighted is invested in the gaslighter. The isolation of the gaslighted person is also important. They can’t turn to a friend and say, “Did you see that?” They’re isolated from perspectives other than the gaslighter’s. And being surrounded by others who believe the gaslighter also has an influence. A lot of social psychologists say we’re inclined to mistrust our perceptions if they conflict with the perceptions of the majority of others around us. EH: So, aside from Ingrid Bergman and Charles Boyer, what are your favorite examples of gaslighting? How about Orson Welles’s infamous radio broadcast of H.G. Wells’s novel War of the Worlds, which told so effectively of Martians invading Earth that it caused mass panic? Or the incident in which Melania Trump wore a jacket that said, “I Really Don’t Care, Do U?” on it to visit migrant children at the Texas-Mexico border. She said it meant nothing, but it caused a media storm of news coverage by those who say she was sending a message. DLS: Well, the War of the Worlds broadcast was not deceptive. Welles did not intend it to produce a misleading impression, but it was so well done that there were many people who believed it. The jacket incident was incredibly disturbing. And even more so was the sheer bizarreness of the disavowal of it as innocuous. That’s gaslighting. She knew damn well what she was doing. EH: Any others? DLS: When I think of examples of gaslighting I think of the Third Reich and the activities of authoritarian leaders all over the world who churn out propaganda to get us to see the world in ways we wouldn’t otherwise see it, and therefore do things we wouldn’t otherwise do without protest. One of the really striking examples is genocides, which I’ve studied quite a bit. Every genocide — for example, those that occurred in the Holocaust, Cambodia, and Rwanda — is aimed at saving the world from some terrible evil. They are highly moralistic activities. Those who participate are convinced that they are doing good, when they know they’re not. They don’t start out there; they have to be brought to that position. EH: But these public examples don’t involve people who are isolated. People are plenty able to — and do — share opinions. How do people get to a place where they believe it? DLS: Well — and this will sound paradoxical — people are often isolated in groups. They surround themselves with those who affirm and reinforce their biases. This has always been an issue, but social media has made it much easier for whole subcultures to insulate themselves from evidence that would call their beliefs into question. EH: The president has tweeted or spoken statements that are demonstrably not true. DLS: It’s typical of an authoritarian style of leadership that the will of the leader defines what is true. In other words, truth is whatever the leader claims to be true. Trump is, without question, an authoritarian leader and his rhetoric follows precisely that pattern. EH: What happens to a person who is not sure if they are being told the truth? What challenges do they face and does it change how they behave about the truth? DLS: There are two paths that people can take. The first is to be skeptical of what they are being told. The second is to smother their doubts and swallow whatever they are told, no matter how absurd. In politics, the followers of a politician are likely to take the second path and the opposition is inclined to take the first. Ideological loyalties have a huge effect on our ability to be honest, critical thinkers — and that spells trouble for democracy. EH: What kind of trouble does it spell for the individual in terms of stress? It’s stressful to wrestle with a challenge to your perception of reality, correct? You still have to take a reckoning of the landscape and decide which way you think is up. DLS: We certainly make things easier on ourselves by drinking the Kool-Aid. If you can convince yourself that the lies of a person who has power over you, or who you admire, or whose affection you wish to have are actually true, you insulate yourself from psychological conflict. This is precisely what devotees of politicians like Trump do. They idealize the leader and take what the leader says as true by definition. Even if the leader says things that are transparently false — for instance, Trump’s remarks about the size of the audience at his inauguration — devoted followers tend to interpret his remarks as true. To do otherwise would be to lose a precious illusion. It is important to understand that political zeal is often profoundly irrational. Followers look to the leader for salvation from the pains, terrors, and humiliations of life. That’s an immensely powerful thing, and it’s not easily questioned or abandoned. EH: Are there any telltale signs that someone is attempting to gaslight you? DLS: People are always looking for a formula; there isn’t one. My advice is: Trust your gut feelings. They are not always right, but they should be taken seriously. EH: Technology has made this so much harder. We can use it, for example, to simulate people’s voices and make us think they said something that they didn’t say. Videos and photographs can be doctored in ways that many experts would have difficulty identifying. Are we facing a new and far more stressful era of deception? Do we need new defense skills? DLS: Every improvement in communication also presents an improved environment for proliferating lies, and the new technologies are no exception. Truth and lies are locked into an arms race, and it isn’t clear which of them, if either, will triumph. EH: What can you do to protect yourself from gaslighting if the telltale signs emerge? DLS: You can’t be gaslighted if you don’t take it on board. People get disoriented when they take stuff on board and buy in. It can help to get a trusted friend’s point of view, but of course this isn’t foolproof. You might also express your concerns to the person whom you suspect is gaslighting you. If that person doesn’t take you seriously, it’s a very bad sign. EH: Is there anything else that will protect us? DLS: First, I think education is essential. You can’t successfully fight deception unless you know why what you know to be true is actually true. Falling prey to conspiracy theories and patently false explanations flourishes in the darkness of ignorance. And this requires support for our educational institutions — adequate funding for K–12 schools and adequate pay for teachers, affordable higher education that’s accessible for ordinary Americans, and halting the rot of colleges and universities turning into little more than job-training centers. Freedom of speech is also essential. Legal protections that allow us to challenge those who would seek to deceive and exploit us are vital, but unless we have a reasonably well-educated, discerning populace, freedom of speech is nowhere near adequate.