Looking straight down is a hot-spot for lying.
Hardly. It is one of the so-called “Italian Pantomimes” of lying, but in many cultures (such as several Hispanic ones) looking down when being addressed is a sign of respect.
By showing you a card trick I'll divert attention away from me.
Really? Since it's a regular trope I would think it means “pay more attention.” I'm positive that Penn and Teller do card tricks to get more attention. Not to hide from it.
Legs straight but body twisted means he's misleading the interrogation.
Looks more like a “flight” response to me. People who deliberately mislead frequently are much more relaxed. They know believing the lie themselves is half the battle.
Looking down and to the right means I have rehearsed my story.
Let me tell you the whole “looking to a direction” thing is overrated. As someone that's studied the psychology of neuromuscular systems I can certify to you that people are not frequently in control of what their eyes are doing...or even aware of it. If the eyes are the window of the soul then they have been boarded up and painted over as far as a psychologist is concerned.
Standing in front of a wall means your collecting yourself before lying.
So someone who composes themselves before speaking is always a liar? They couldn't possibly be coping with their emotions. Or recalling facts. Or thinking they are regretting the indigestion those cheese fries are giving them.
Leaning forward is a sign they are not withholding information.
Or it could be a sign they are confident in their mistruth. See the “Italian Pantomimes” mentioned above.
Tense facial muscles say “guilty”.
They can also say “annoyed”. Or “constipated”.
Arms crossed is a hotspot that he's withholding the truth.
Actual body language scientists agree that arms crossed is a signal of “I'm done listening to you.” or “I am closed to your opinion.”
A false smile, a tight hug, and a hand in the pocket indicate a psychopathic persoanlity.
It the beloved paraphrased words of Wednesday Adams: “What do serial killers look like? Everyone else.” Which is exactly why they are successful. Never forget that.
He's using the chair as a “psychological shield”.
Freud died in 1939. His opinions like this died only a few decades afterward. Yet we still love using them.