That's a pertinent question in relation to the article submitted here. The main answer to your question is that there don't seem to be any invariant behaviors,

That's a pertinent question in relation to the article submitted here. The main answer to your question is that there don't seem to be any invariant behaviors, or even reliable behaviors, associated with lying.[1] Some people are "naturally" capable of lying shamelessly, and many other people can be trained to lie while beating any lie detection system based on physical signs. The best methods for detecting lying when (for example) conducting a police investigation or engaging in foreign intelligence is to analyze the liar's statements for inconsistencies. Statement analysis that prompts new questions in a structured interview is the best way to detect deception, because it's hard to make up a consistent set of story details in advance when making up a story. [1] http://www.slate.com/articles/technology/future_tense/2013/06/polygraphs_and_other_lie_detection_technologies_may_never_really_work_in.html http://www.slate.com/articles/technology/future_tense/2013/0... http://www.people.com/people/archive/article/0,,20079233,00.html http://www.people.com/people/archive/article/0,,20079233,00.... http://www.amazon.com/A-Tremor-In-The-Blood/dp/0306457822 http://www.amazon.com/A-Tremor-In-The-Blood/dp/0306457822 [2] http://leb.fbi.gov/2011/june/evaluating-truthfulness-and-detecting-deception http://leb.fbi.gov/2011/june/evaluating-truthfulness-and-det... https://books.google.com/books?hl=en&lr=&id=5GjTLtibmXYC&oi=fnd&pg=PA41&dq=lie+detection+statement+analysis&ots=jTavMvNxPD&sig=fHfbYK6rg016vl20njSLrrCmkrs#v=onepage&q&f=false https://books.google.com/books?hl=en&lr=&id=5GjTLtibmXYC&oi=...