avoiding: A relational stage in which one or both individuals in a couple try to distance themselves from each other physically. For example, Owen changes jobs to have an excuse to travel away from home frequently.

beautiful-is-good effect: A tendency for physical attractiveness to create the perception of competency and intelligence. For example, a witness is viewed favorably and seems credible because she is good-looking.

birds-of-a-feather effect: A tendency to be attracted to others if we perceive them to have similar levels of physical attractiveness, values, and interests.

bonding: A relational stage in which an official, public ritual unites two people by the laws or customs of their culture. For example, Ruth marries Owen in her hometown church.

circumscribing: A relational stage in which partners avoid talking about topics that produce conflict. For instance, whenever Owen mentions he’s interested in moving, Ruth becomes upset and changes the subject.

commitment: A strong psychological attachment to a partner and an intention to continue the relationship long into the future.

companionate love: An intense form of liking defined by emotional investment and interdependent lives.

differentiating: A relational stage in which the beliefs, attitudes, and values that distinguish you from your partner come to dominate your thoughts and communication. For example, Ruth and Owen argue over whose family they are going to visit for Thanksgiving and how little time he has spent helping her fix up the house.

equity: The balance of benefits and costs exchanged by you and a romantic interest that determines whether a romantic relationship will take root (after attraction is established).

experimenting: A relational stage in which two people become acquainted by sharing factual information about themselves and making light conversation or small talk. For instance, after Ruth is introduced to Owen, they talk about their jobs and where they went to school, and they discover they both like jazz.

initiating: A relational stage in which two people meet and form their first impressions of each other. For instance, Owen introduces himself in a message to Ruth after reading her profile in an online dating site, and she responds with her telephone number.

integrating: A relational stage in which two people become a couple and begin to share an identity. For example, Ruth and Owen share an apartment together and spend time with each other’s families.

intensifying: A relational stage characterized by deeper self-disclosures, stronger attraction, and intimate communication. For example, Owen and Ruth have been dating for more than a year and talk with excitement about a future together.

jealousy: A protective reaction when a valued relationship seems threatened. For instance, Tyler is jealous when his girlfriend, Mary, flirts with Scott.

liking: A feeling of affection and respect typical of friendship.

loving: An intense emotional commitment based on intimacy, caring, and attachment.

matching: A tendency to be attracted to others whom we perceive to be at our own level of attractiveness. For example, Michael dates Jennifer because she is pretty but not unapproachably gorgeous.

mere exposure effect: A phenomenon in which you feel more attracted to those with whom you have frequent contact and less attracted to those with whom you interact rarely. For example, the more June sees of Tom, the more attracted to him she becomes.

passionate love: A state of intense emotional and physical longing for union with another.

reciprocal liking: When the person we’re attracted to makes it clear, through communication and other actions, that the attraction is mutual.

relational dialectics: Opposing tensions between ourselves and our feelings toward others that exist in interpersonal relationships, such as the tension between wishing to be completely honest with a partner yet not wanting to be hurtful.

relational maintenance: Efforts that partners make to keep their relationship in a desired condition. They may show devotion by making time to talk, spending time together, and offering help or support to each other.

romantic betrayal: An act that goes against expectations of a romantic relationship and, as a result, causes pain to a partner.

romantic relationship: An interpersonal involvement two people choose to enter that is perceived as romantic by both.

social exchange theory: The idea that you will be drawn to those you see as offering substantial benefits with few associated costs. For example, Meredith thinks Leonard is perfect for her because he is much more attentive and affectionate than her previous boyfriends and seems so easy to please.

stagnating: A relational stage in which communication comes to a standstill. For instance, day after day, Owen and Ruth speak only to ask if a bill has been paid or what is on television, without really listening to one another’s answers.

terminating: A relational stage in which one or both partners end a relationship. For instance, Ruth asks Owen for a divorce once she realizes their marriage has deteriorated beyond salvation.

wedging: When a person deliberately uses online communication—messages, photos, and posts—to try to insert him- or herself between romantic partners because he or she is interested in one of the partners.