Detecting when you are being lied to, or gamed, or otherwise being manipulated, is an essential skill if you wish to protect yourself from people who seek to abuse your trust and find personal and confidential information that can be used against you.
It’s not just criminal gangs, nor even malicious foreign governments, although they are out to get you. Sometimes it’s the person you think you know, playing on your trust and goodwill. I’ve already mentioned this as the greatest danger to your privacy and information security.
The more you learn about the science of detecting lies, the better you can be about protecting yourself. http://www.social-engineer.org/tactics/the-truth-about-eye-contact-and-detecting-deception/ shows that conventional eye contact beliefs are the myths they always were. “Look me in the eye and say that.” – a good liar will have practiced it over and over — it’s the amateurs and hobbyist liars who break under scrutiny.