Lying becomes automatic with practice

Forget shifty eyes or fidgety fingers, psychology research has shown that these supposed signs of lying are unreliable. Liars easily learn to make eye contact, and anxiety can make honest people squirm nervously.

A more useful foundation for lie-detection is the simple fact that lying is more cognitively demanding than telling the truth. False answers therefore usually take slightly longer than honest responses, especially when a suspect is burdened with an extra mental challenge, such as telling their story backwards.

However, a new study suggests that the cognitive demands of lying can be reduced with practice. Xiaoqing Hu and his team presented 48 participants with dates, place names and other information and asked them to indicate with one of two button presses whether the information was self-relevant or not. In real life this would be equivalent to a suspect posing as a different person. Instructed to lie, the participants took longer to respond than when they told the truth, consistent with the well-established idea that lying is cognitively demanding.

Next, a third of the participants were told about the reaction time difference and given extensive practice (360 trials) at lying more quickly about the self-relevance of information. The requirement to get faster was made explicit because past research found lying practice without such an instruction was ineffective. On retesting, the trained participants in the current study no longer took more time to answer dishonestly compared with telling the truth. “Deception is malleable and its performance index can be voluntarily controlled to be more automatic,” the researchers said.

Another group had no training but were told about the reaction time difference between lying and truth telling, and encouraged to answer faster when lying. They got faster at lying compared with a control group, but still they were speedier when being honest.

The researchers admitted that their sample size was small and a replication is needed with more participants. However, they said their results suggest that to be more realistic, lie-detection research based around the cognitive demands of lying should incorporate the effects of practice.


Hu, X., Chen, H., and Fu, G. (2012). A Repeated Lie Becomes a Truth? The Effect of Intentional Control and Training on Deception. Frontiers in Psychology, 3 DOI: 10.3389/fpsyg.2012.00488

Also published recently: Sorting the Liars from the Truth Tellers: The Benefits of Asking Unanticipated Questions on Lie Detection.

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

5 thoughts on “Lying becomes automatic with practice”

  1. Nice post valuable information about Lying practice .Keep up your good work doing

    Great experiment using cognitive psychology to be able to tell the difference when someone is telling the truth or telling a lie based on the time it took them to tell it. Does lying really become automatic, I’m not sure, but I do believe that someone can train themselves to mask their lie as truth effectively. The person still has to first decide if they’re going to tell the truth or a lie before they tell the truth/lie.

  2. Its interesting knowing that the brain can be trained to lie when practiced. People can put on such called bluffs and make them seem almost realistic and believable. Studies show that the brain can not be trained to lie but it can change into another personality in a person.

  3. Very intriguing. I must agree with the post above that lying is learned and as a result, it can alter a person's personality. The mind is a powerful thing. Over time and with much thought, we can manipulate our cognitive processes to say false statements. With much practice, I believe a person can become a “professional liar.” That meaning they are not giving any communication whatsoever that they are lying. I believe this experiment is a great way to use cognitive psychology. Props to those who are involved!

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