Excerpt from The Sociopath Next Door by Martha Stout, plus links to reviews, author biography & more

As a psychologist, I am persuaded most by a feature of the story we have not even addressed until now—the fact that Joe feels affection for Reebok. He is emotionally attached to his dog. Reebok follows Joe around the house, and Joe likes it. Joe gazes into Reebok's eyes. Reebok has changed Joe from a trophy pet owner to a smitten pet owner. And on account of this attachment, I believe that when Joe gave up his morning plan and went home to take care of his dog, he may possibly have been acting out of conscience. If we could give Joe a truth serum and ask him what was going on inside him at the moment he decided to turn the car around, and he were to say something like, "I just couldn't stand it that Reebok was going to be there hungry and thirsty all that time," then I would be reasonably convinced that Joe was conscience-driven in this situation.

I would be basing my evaluation of Joe on the psychology of conscience itself. Psychologically speaking, conscience is a sense of obligation ultimately based in an emotional attachment to another living creature (often but not always a human being), or to a group of human beings, or even in some cases to humanity as a whole. Conscience does not exist without an emotional bond to someone or something, and in this way conscience is closely allied with the spectrum of emotions we call "love." This alliance is what gives true conscience its resilience and its astonishing authority over those who have it, and probably also its confusing and frustrating quality.

Excerpted from The Sociopath Next Door by Martha Stout, Ph.D. Copyright © 2005 by Martha Stout, Ph.D.. Excerpted by permission of Broadway, a division of Random House, Inc. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.