Can You Handle the Pressure?

Marcus Reyes


Can lie detecting be done without a machine?


The purpose of this experiment is to see if there is a possibility to do lie detecting naturally.


If I apply force on a person's arm, then the amount of resistance given back will determine if the person is lying or telling the truth because of the tension that body holds from their response.

  • Lying has become a societal norm that we do on a daily basis to get out of situations
  • Some people get comfortable when telling lies (if they tell a lot of them too!), for others it is easily noticeable.
  • Being under pressure, like lying, could make the person tense. However, too much tension can lead to stress.
  • Your heart tells you that its better to tell the truth, but our brain signals us to lie, and you can't resist.
  • Influences that love connections and getting active can help stop the excessive lying.

  • Independent Variable: The independent variable is the responses given from the participants.
  • Dependent Variable: The dependent variable is the resistance from pushing the arm down.
  • Control Group: The control group is the truth and lies given from the participants.
  • Constants: Some constants in this experiment is the questions, the amount of pressure on the arm, and the person that is applying the pressure.


Variables of the Experiment

  • Human Participant
  • Blank pieces of papers for recording data and observations
  • Pencil or pen


  1. Have the participant stand up straight and face towards you.
  2. Have you and the participant extend an arm out in front of them with their palm facing down.
  3. Place your hand over their arm, preferably on or above the wrist.
  4. Inform the participant about the questions and tell them that they must give one true statement and one statement that is a lie.
  5. Ask the participant for their first statement.
  6. Let the participant respond with an answer.
  7. Gently apply steady pressure to the participants arm and push it down for a few seconds.
  8. Record observation on how hard it was to push down.
  9. Repeat steps 5-8 one more time with the second statement.
  10. Ask the participant which statement they lied about. Record the answer.
  11. Analyze the data.


Charts & Graphs


Conclusion: As people gave their two statements, the lie statement became known due to the person becoming tense and resisting very hard.

From the observations shown from the data, there was a pattern that was recognized. The participants that I got a wrong guess from were all female. This could prove that women can hide secrets from others better than m5en, but it cannot be scientifically proven just from this experiment.


  • As people gave their two statements, their lie statement became known due to the person becoming tense and resisting very hard.
  • Due to the resistance given by each person, I was able to get a majority of 86% correct answers, while I had 14% incorrect guesses from a total of 50 trials.
  • WHY?: They hurry to think of something in their brain, and become tense about it because they know they're lying. They stress, but try to keep their composure and act like they can keep a good secret.
  • The participant built up tension inside their body to mask it, but when tested, they held that tension and it showed that it was very hard to push their arm down.
  • Truths are easier for people because they already have a mellow, relaxed composure. They do not have to process and create something false in their mind because they have a clear picture of that thing, person, or event.


This experiment could easily have had some mistakes that could falsify the data. The easiest problem that I could have done would be that I did not apply the same amount of pressure on the person’s wrist. That would change the observations on each person and each test. That leads to the entire data to be inaccurate and not useable for the experiment.


  • The experiment applies to real life because it is a natural way of detection of a liar. It’s not a 99% correct polygraph test, but it is fairly reliable and useful when that technology is not available.
  • Could possibly cease the use of a polygraph and it each person would gain the knowledge of testing to see if someone is lying or not.
  • This experiment can be improved by testing it on more age ranges than just 14-16 year olds. Older and younger people have a different mindset and may act differently when saying truth and lies.
  • If consistent, then we can find the small kinks and fix them to make it an actual test of detection instead of wiring someone to a machine to see if they are lying.

Thank You For Watching!!

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