How to Detect Lies
To detect if someone is lying, watch to see if they touch their nose or cover their mouth while they're talking, which could be a sign that they're not telling the truth. Also, listen carefully to the person's voice. If it's higher-pitched or if they're stuttering and stammering a lot, it could mean they're lying to you. You can also keep an eye out for physical signs of nervousness, like sweating, fidgeting, or fast breathing, which may indicate that they're nervous because they're hiding something.
Liars may want to hide their face so you aren’t looking at them while they tell you untruths. Notice if they put a hand over their eyes so you can't make eye contact. Additionally, consider if they keep bringing their hand to their mouth. These might be signs the person is lying to you. They may not totally cover their eyes or mouth. For instance, they might place a hand over the side of their face so 1 eye is hidden. Similarly, they might touch their lips so their hand is covering most of their mouth. A liar may press their lips together in a tight smile that doesn't reach their eyes. They may be trying to hide their real facial expression by forcing a smile. A real smile will cause crow's feet around the person's eyes. This is less reliable if the person had Botox in the past. Botox can freeze the area around a person's eyes so they won't get crow's feet. Studies show that eye contact has nothing to do with truthfulness, but that doesn’t mean a person's eyes can’t help you figure out if they’re telling the truth. When someone's lying, they may start blinking faster than they normally do. Make eye contact with them to see if their blinking changes. If the person you suspect might be lying suddenly starts blinking fast, it's possible they're not being truthful. For example, let's say you just asked them a question. If they start blinking really fast before they answer, they might be trying to lie to you. Someone who is spouting lies may feel super self-conscious about their mouth. Additionally, they'll likely feel nervous. Often, these emotions cause them to start biting or chewing their bottom lip. Watch for this behavior if you suspect someone might be lying to you. For instance, they might chew on their lip while you're asking questions or might nibble their lip after giving an answer. Flared nostrils are a micro-expression that might mean a person is lying. Sometimes this happens because the person is feeling defensive, since they're worried you'll catch onto their lie. Watch their nose while they're speaking to see if their nostrils flare out. Try asking them a question, such as, “Can you tell me again what happened?” or “If you didn't do it, who did?” Then, observe their nose as they answer. Keep in mind that flared nostrils can also have other meanings, such as anger or fear. A liar may start sweating because they're feeling nervous. Look at their temples, around their lips, and at their underarm area to see if they're sweating. Then, consider if the temperature may be causing the sweating. The person's temple and hairline will likely be the most noticeable place at first. If it's hot outside, they may be sweating because of the heat. In that case, rely on other signs to check if the person may be lying. They may start twirling their hair around their finger or running their hands through their hair. They may also rub their facial hair if they have any. Watch for these behaviors if you suspect a person may be lying. For example, the person may start twirling their hair around their finger or may even braid the ends of long hair. If the person has facial hair, you may notice them running their fingers along it or adjusting the ends. Pay attention to how often they're doing this. They're more likely to be lying if they play with their hair or beard throughout the conversation. A person who’s lying will likely have trouble making normal hand gestures. In some cases, they may feel like they need to hide their hands. Observe their hand movements to check for things like putting their hands in their pockets or placing their hands behind their back. You might also notice things like hand wringing or touching random items. For example, they might start cracking their fingers or may play with a button on their shirt. Lying makes you feel nervous, so your body may tense up. This may affect the sound of your voice. Their tone of voice may go up higher or could drop lower. Consider any changes in tone as a possible sign of lying. Let's say someone is telling a story about what they were doing last night and suddenly their voice gets really high. They may have started telling you a lie. A liar may slow down their speech while they think up their lie, but they may speak faster when repeating a rehearsed lie. It's common for liars to change how fast they're speaking during a conversation. Pay attention to the pace of their speech to help you figure out if a person may be lying. For instance, they may initially rattle off a story super fast. When they try to answer questions about the story, they may speak really slowly as they make things up. Typically, a liar will change the way they tell the lie as they get more comfortable with their story. You may notice sentence fragments when they're trying to make things up. On the other hand, they may switch to more complex or run-on sentences as they try to convince you of their story. Pay attention if the person suddenly swings between short, incomplete sentences and very long, complex sentences. As an example, they might start out with statements like, “Just me,” “At school,” and “Right home.” Later, you might notice sentences like, “I was totally alone last night, you can check with my friends. It was just me there, so there's no reason to be suspicious.” A person who is lying has to make up a story, so they'll likely struggle to fill in the details. When you ask for more information, they'll barely expand on what they already told you. Notice if someone isn't sharing many details with you because they may be lying. Let's say you suspect your partner is lying about studying at the library instead of going out with friends. They might say things like, “The library was quiet last night” or “It was really busy.” You could ask questions like, “About how many tables were empty?” “Which librarian was on duty last night?” or “Which books did you review last night?” to see if they add more details. Normally, people take a moment to think about the answer to a question before they give it. However, a person who's lying will often answer right away because they've rehearsed their answers. Ask the person several questions in a row to see if they take time to think about it or answer right away. If they seem to have all of the answers, they might be lying to you. You might ask questions like, “What happened after that?” “Who else was there?” “Where were you before that?” or “Can you describe the scene?” If the person gives a short, non-detailed answer that covers a long period of time, it may be a sign they're lying. Open-ended questions force the person to add onto their story. Not only is this more work for them, it also digs their hole deeper if they're lying. Pepper the person with questions that require more than a yes/no answer so they have to think. You might ask, "Who else was there?" instead of "Were you alone?" or "What classes did you take last semester?" rather than "Were you a student last semester?" Try to ask unexpected questions because it'll stress them out more. For instance, "What song was playing when you got there," or "Which bartender was working last night?" might trip up a person who's making things up. Liars may be really good at telling a rehearsed lie, but asking them to tell it backward usually trips them up. When a person is telling the truth, they can usually go through their memories to easily reverse their story. However, a liar will have to work extra hard to reconstruct their lie. Ask the person to tell you the story backward and see how well they do it. Say, “Okay. Can you tell me what happened again, but this time start at the end of the story and go backward?” When someone’s lying, they often need extra time to think of an answer to your questions. Because of this, they'll try to buy time by repeating a question before they answer it. Be on alert if a person keeps doing this, as they might be lying. You might ask, “Where were you last night?” only for them to respond, “Where was I last night? Oh, I was at home.” As another option, they might compliment your question to buy time. Listen for statements like, “That's a good question,” or “Thank you for asking that.” You might be able to catch a person in a lie by fact checking their story. Make a note of any details you can verify later. Then, see if what the person told you was true. For instance, let's say your coworker says they ate lunch at a local cafe, but you suspect they stole your lunch. You might ask them what the cafe's special is that day so you can verify that detail. Similarly, maybe you suspect the person you're dating is lying about their education. You might ask them the name of their degree and the professors they studied under. You can then check if the school they claim they attended has that degree and employs those professors. A liar wants you to believe them, so they may directly tell you that they’re being truthful. Statements like “It's the honest truth” or “I don't want to lie to you” are a big red flag that the person is lying. Anytime you hear these phrases, look closer at the person's story because they could be lying. They might say things like, “To be honest with you,” or “I want to tell you the truth.” If this happens, it's a good idea to ask more questions and pay careful attention to how they respond. 
Liars may want to hide their face so you aren’t looking at them while they tell you untruths. A liar may press their lips together in a tight smile that doesn't reach their eyes. Studies show that eye contact has nothing to do with truthfulness, but that doesn’t mean a person's eyes can’t help you figure out if they’re telling the truth. Someone who is spouting lies may feel super self-conscious about their mouth. Flared nostrils are a micro-expression that might mean a person is lying. A liar may start sweating because they're feeling nervous. They may start twirling their hair around their finger or running their hands through their hair. A person who’s lying will likely have trouble making normal hand gestures. Lying makes you feel nervous, so your body may tense up. A liar may slow down their speech while they think up their lie, but they may speak faster when repeating a rehearsed lie. Typically, a liar will change the way they tell the lie as they get more comfortable with their story. A person who is lying has to make up a story, so they'll likely struggle to fill in the details. Normally, people take a moment to think about the answer to a question before they give it. Open-ended questions force the person to add onto their story. Liars may be really good at telling a rehearsed lie, but asking them to tell it backward usually trips them up. When someone’s lying, they often need extra time to think of an answer to your questions. You might be able to catch a person in a lie by fact checking their story. A liar wants you to believe them, so they may directly tell you that they’re being truthful. 