The common-sense view of people who cheat is that they are vain and selfish and mostly out for themselves and their own needs. They do not care how much someone else suffers or how much they cause it as long as they get what they want.
Social scientists who study people who cheat on their partners actually confirm this common-sense view of infidelity. A cluster of personality traits like selfishness and lack of feeling for others together make up a personality disorder called “narcissism.” While not everyone who cheats is a narcissist, people with those traits are more likely to be unfaithful and enter into a series of short-term relationships with the opposite sex.
A narcissist lover works something like a flashlight battery. The light is beautiful, but it burns out fast. The average narcissist, according to a study from the University of Alabama, has relationships that turn sour after about four months. The thing is that they are so good at first impressions that they can quickly find another relationship to replace it.
Narcissists tend to be physically more attractive than average, and they have great self-esteem. They dress well and carefully groom themselves. Female narcissists prefer sexy clothing. They were more popular in school than most students. Male narcissists (and there are more narcissistic men than women) tend to brag, be witty and talk in loud voices, but both sexes dominate conversations and act bored when others are talking.
Narcissists make great first impressions because they tend to more attractive, intelligent, and charismatic than others and because they know how to manipulate other people. They walk into a party and immediately “own” the room.
Narcissists see other people as objects they use to further their self-interest. And they are only interested in themselves and their goals, most often to be unrealistically successful, rich, and famous. They make friendships based on what the other person has that benefits them — they prefer people who are wealthy, beautiful, well-connected, etc. They use their charm and intelligence to get what they want and drop those who are no longer useful to them.
Narcissists tend to be jealous lovers. They over-react, usually by getting angry, if a partner criticizes them or shows too much independence. They need you to constantly admire them. As your relationship starts to mature and you start treating them in a normal way, they move on to someone who will worship them. They are actually more likely to cheat when they believe a partner is committed to them.
Dr. Jonason of the University of South Alabama and certain other psychologists believe that narcissism may be a “sexual style” that evolved over time as a way of successfully ensuring a variety of fertile sexual partners.
Dr. Robert Emmons was the first to write about the paradox of narcissism, which is that although a narcissist devalues other people, he desperately needs them to admire him. In other words, you can get over an affair with a narcissist and find a healthy romantic relationship, but like that flashlight battery, he will just keep going and going and going and going on to someone new.