Deception detection between relational partners is extremely difficult unless a partner tells a blatant or obvious lie or contradicts something the other partner knows to be true. While it is difficult to deceive a partner over a long period of time, deception often occurs in day-to-day conversations between relational partners. Detecting deception is difficult because there are no known completely reliable indicators of deception and because people often reply on a truth-default state. Deception, however, places a significant cognitive load on the deceiver. He or she must recall previous statements so that his or her story remains consistent and believable. As a result, deceivers often leak important information both verbally and nonverbally.