How to Tell If Someone Is Lying

A Person Proclaims His Honesty Repeatedly

To sell us on the integrity of their answers, liars often use phrases emphasizing the validity of their statements, like “to tell the truth” and “to be perfectly honest.” These verbal tip-offs frequently invoke religion. Think of expressions like “I swear on a stack of Bibles” and “as God is my witness.” Most truthful people don’t need to go that far.

Joseph Buckley is the president of John E. Reid and Associates, in Chicago, which trains law-enforcement investigators.