Secrets from the CIA, FBI, and Special Forces on how to know if someone is telling the truth

In 2015, star NFL quarterback Tom Brady and his New England Patriots were mired in a scandal known as “deflategate.” The team and its popular player were accused of deflating footballs, which was illegal as it would make them easier for their offense to handle. When Brady met with reporters he was asked a direct question: “Tom, were you involved in deflating the footballs?” He responded, “I would never do anything outside of the rules of play.” 

You might notice that Brady didn’t directly answer the question, and that is one of the red flags that FBI agents and other law enforcement officers use to assess individuals and figure out whether they are telling the truth. 

If you could train someone to be “a human lie detector”—as some former FBI agents and intelligence officers claim to be able to do for their corporate clients—then you’d be very successful. Every corporate titan would want you on their team to ascertain whether their counterparty in a negotiation is deceiving them. The truth is that humans are too complex and no one can tell you with any high degree of certainty whether someone is lying. Even a polygraph test isn’t foolproof. 

We can, however, evaluate how a person responds to certain questions and how their body language changes throughout a conversation, providing valuable clues to evaluate whether they are telling the truth. 

Brady’s response displayed one of these red flags: He failed to answer the question. Let’s talk about a few other red flags to keep in mind to help you detect deception. 

If you’re a company’s chief security officer questioning an employee suspected of taking hundreds from petty cash, you might ask them directly if they took the money. Perhaps they reply, “Well, petty cash gets used for a lot of things around here,” and list those random things in a meandering response. That person didn’t admit to anything, but what they’ve given you is what’s known as a “nonanswer statement”—another red flag. 

Perhaps the CSO asks the same question and the respondent says, “Did I take the money?” and looks around the room like the answer is floating around the room. When someone repeats a question, they are often buying time to consider how to answer. If they are telling the truth they would just candidly answer the question. 

Picture a gangster movie, in which a criminal cohort asks if one of their accomplices is working with the police. The gangster swears on the lives of his children that he isn’t a rat. Off-screen, if someone answers so adamantly and invokes dramatic oaths, you should be concerned about the lengths they’re taking to convince you. Innocent people are typically less dramatic because they are sure of the truth. 

Paying attention to body language is an essential component in the ongoing process of assessing a person’s truthfulness. There’s an often-used phrase: “What the mind conceals, the body reveals.” For instance, if a detective finishes questioning someone, they might say, “Thanks for your time. If we have further questions could we get back in touch?” That person might say, “Sure, no problem” while shaking their head; while their mind knows they should say yes, their subconscious is giving away their unease. 

When you sit down with a person across a conference table, you might make small talk to break the ice. During these exchanges, you should try to measure what’s considered that person’s baseline of behavior. Are they someone who uses a lot of hand gestures when speaking or do they sit placidly as they speak? Are they fidgeting as they talk and listen to you? 

Once your conversation gets more detailed, note whenever they deviate from that baseline. If you mention the price for your product or service, do they reach back and rub their neck while telling you that sounds fine? If so, they might be deceiving you. Not only are they deviating from their baseline but they are also unknowingly employing a soothing gesture (rubbing their neck)—a potential attempt to calm their disquiet about your pricing without expressing their concern out loud. Familiarize yourself with other soothing gestures such as the stroking of legs or rubbing of hands and watch when they are utilized as a deviation from the baseline. 

Law enforcement will often seat a suspect at a table and place a pen or a paper clip nearby, or put them on a chair with wheels. They will then watch when the suspect begins to play with the pen or paper clip, or when they start to roll around on their chair, and the interrogator will note what question caused the behavior change and consider what that might mean about their truthfulness. 

Perhaps you’re now considering your own behaviors—how you might occasionally repeat a question because you didn’t hear it well or because it’s complex and requires a follow-up. Or there might be other considerations, like a person’s fidgeting could be because they’re late for another meeting or anxious about something totally unrelated.

No one of these methods, or any method, is a panacea to ferret out lies. But CIA case officers and FBI agents will tell you that by employing these techniques and putting together an overall picture, factoring in all the details available, you can make better decisions about someone and how much you can trust them.