gullibility while still exercising empathy. In the first part of "Little Red Riding Hood", the title character is deceived by a wolf; from this experience she learns to feign gullibility in order to deceive a second wolf. In "The Emperor's New Clothes", the emperor and his staff display gullibility in being swindled, while the crowd displays credulity in believing in the invisible cloth. Mark Twain depicts mass gullibility in The Adventures of Tom Sawyer and The Gilded Age: A Tale of Today, among others. Shakespeare explores gullibility in the title characters of Romeo and Juliet, Macbeth, and especially Othello. Of the examples of deception found in the Bible, the tale that most concerns the behavior of the deceived is Samson in the Book of Judges, a character who is destroyed by his gullibility in the face of love. The best-known example is Eve's gullibility in the Book of Genesis. Deception is a classic theme in war and politics—see The Art of War and The Prince—and Greenspan finds the example most concerned with the gullibility of the deceived to be the Trojan Horse. In the Aeneid's version of the story, the Trojans are initially wary, but vanity and wishful thinking eventually lead them to accept the gift, resulting in their slaughter. Greenspan argues that a related process of self-deception and groupthink factored into the planning of the Vietnam War and the Second Iraq War. In science and academia, gullibility has been exposed in the Sokal Hoax and in the acceptance of early claims of cold fusion by the media. In society, tulipmania and other investment bubbles involve gullibility driven by greed, while the spread of rumors involves a gullible eagerness to believe (and retell) the worst of other people. April Fools' Day is a tradition in which people trick each other for amusement; it works in part because the deceiver has a social license to betray the trust they have built up over the rest of the year. Theories Some writers on gullibility have focused on the relationship between the negative trait of gullibility and positive trait of trust. They are related, as gullibility requires an act of trust. writes that exploiters of the gullible "are people who understand the reluctance of others to appear untrusting and are willing to take advantage of that reluctance." In 1980, Julian Rotter wrote that the two are not equivalent: rather, gullibility is a foolish