The term emotional affair is used in the media to categorise or explain a certain type of relationship. The Diagnostic and Statistical Manual of Mental Disorders, 4th. Edition does not define the term, and its definition is therefore considered anecdotal and subjective.
High levels of non-sexual emotional intimacy in adults may occur without the participants being bound by other intimate relationships or may occur between people in other relationships. "Attachment Theory" research reflects both constructs.
The term often describes a bond between two people that mimics the closeness and emotional intimacy of a romantic relationship while never being physically consummated. An emotional affair is sometimes referred to as an affair of the heart. An emotional affair may emerge from a friendship, and progress toward greater levels of personal intimacy and attachment. What distinguishes an emotional affair from a friendship is the assumption of emotional roles between the two participants that mimic of those of an actual relationship - with regards to confiding personal information and turning to the other person during moments of vulnerability or need.
An emotional affair can be defined as:
"A relationship between a person and someone other than (their) spouse (or lover) that affects the level of intimacy, emotional distance and overall dynamic balance in the marriage. The role of an affair is to create emotional distance in the marriage."
In this view, neither sexual intercourse nor physical affection is necessary to affect the committed relationship(s) of those involved in the affair. It is theorized that an emotional affair can injure a committed relationship more than a one night stand or other casual sexual encounters.
Research by Glass & Wright found that men's extramarital relationships were more sexual and women's more emotional. For both genders, sexual and emotional extramarital involvement occurred in those with the greatest marital dissatisfaction.
Chaste and emotionally intimate affairs tend to be more common than sexually intimate affairs. Shirley Glass reported in Not "Just Friends" that 44% of husbands and 57% of wives indicated that in their affair they had a strong emotional involvement to the other person without intercourse.
In University of Chicago surveys conducted by NORC between 1990 and 2002, 27% of people who reported being happy in marriage admitted to having an extramarital affair. The meaning and definition of what infidelity constitutes often varies depending on the person asked. Sexual feelings in an emotional affair are necessarily denied to maintain the illusion that it is just a special friendship. Affair surveys are unlikely to explore what is denied. Many people in affair surveys are not honest with themselves nor with the interviewer.