Liar, liar pants on fire!

How to Spot a Liar: Why People Don't Tell the Truth and How You Can Catch Them by Gregory Hartley and MaryAnn Karinch is a fascinating read.
Gregory Hartley is a former military interrogator and currently a private consultant. He draws on his military experience to share techniques to help readers expose the liars in their lives. Ann Karinch is an author and literary agent. 
The book can be a little confusing at times as Hartley varies his style. At times he refers to hypothetical cases and at other times he reverts to giving concrete examples of speech patterns and body language that can be used to detect lying. The shift between the two can be jarring, but the material is fascinating and useful.
I liked how Hartley applies the information to real-life situations, such as buying a car or negotiating a raise. After reading the book, I watched a tense negotiation on the TV show Shark Tank between an entrepreneur and three potential investors – the sharks. I could see the exact eye movements and facial expressions Hartley described. It was fascinating.
Hartley says people often lie to be polite or to avoid conflict, and to embellish or gain the upper hand.
This book is required reading for business people. It is also fun for anyone fascinated by human behaviour.