From wikpedia:

Deception is a major relational transgression that often leads to feelings of betrayal and distrust between relational partners. Deception violates relational rules and is considered to be a negative violation of expectations. Most people expect friends, relational partners, and even strangers to be truthful most of the time. If people expected most conversations to be untruthful, talking and communicating with others would require distraction and misdirection to acquire reliable information. On a given day, it is likely that most human beings will either deceive or be deceived by another person. A significant amount of deception occurs between romantic and relational partners.

Types:

Deception includes several types of communications or omissions that serve to distort or omit the complete truth. Deception itself is intentionally managing verbal and/or nonverbal messages so that the message receiver will believe in a way that the message sender knows is false. Intent is critical with regard to deception. Intent differentiates between deception and an honest mistake. The Interpersonal Deception Theory explores the interrelation between communicative context and sender and receiver cognitions and behaviors in deceptive exchanges.

The five primary forms of deception are:

1. lies: making up information or giving information that is the opposite or very different from the truth.
2. equivocations: making an indirect, ambiguous, or contradictory statement.
3. concealments: omitting information that is important or relevant to the given context, or engaging in behavior that helps hide relevant information.
4. exaggeration: overstatement or stretching the truth to a degree.
5. understatement: minimization or downplaying aspects of the truth.

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. 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.

Deception and its detection is a complex, fluid, and cognitive process that is based on the context of the message exchange. The Interpersonal Deception Theory posits that interpersonal deception is a dynamic, iterative process of mutual influence between a sender, who manipulates information to depart from the truth, and a receiver, who attempts to establish the validity of the message. A deceiver's actions are interrelated to the message receiver's actions. It is during this exchange that the deceiver will reveal verbal and nonverbal information about deceit. Some research has found that there are some cues that may be correlated with deceptive communication, but scholars frequently disagree about the effectiveness of many of these cues to serve as reliable indicators. Noted deception scholar Aldert Vrij even states that is no nonverbal behavior that is uniquely associated with deception. As previously stated, a specific behavioral indicator of deception does not exist. There are, however, some nonverbal behaviors that have been found to be correlated with deception. Vrij found that examining a "cluster" of these cues was a significantly more reliable indicator of deception than examining a single cue.

In terms of perceptions about the significance of deceiving a partner, women and men typically differ in their beliefs about deception. Women view deception as a much more profound relational transgression than men. Additionally, women rate lying in general as a less acceptable behavior than men.

Finally, women are much more likely to view any act of lying as significant (regardless of the subject matter) and more likely to report negative emotional reactions to lying.

....Ahem....

-Donni-