A type of cognitive bias in thinking and decision making is illusory correlation. This type of cognitive bias is a belief that two things are associated when there truly isn’t an actual association. Illusory correlation is the occurence when one perceives a relationship between variables, such as people, behavior and situations, even when there may be no real relationship. Availability of information is the key factor in illusory correlations. These correlations are more easily made when a particular event, situation or idea is easily recalled and also when the memory is vivid. The frequency of the occurrence is not relevant as the most important aspect of forming illusory correlations arises from the combined effect of how easily and how vivid the situation is recalled. For example, a man from a rural town travels to New York City. While getting on the subway, someone cuts him off. His waiter from the restaurant where he ate dinner is rude to him. When he asks someone on the street for directions, they blatantly ignore him. When he reflects back on his trip to New York, associates his experiences with the stereotypes that “people from New York are rude” and “people in big cities are rude.” However, he forgets that the waiters from all the other restaurants are well-mannered and the thousands of people who didn’t cut him off on the subway. It is easier to remember specific moments such as when someone acted rudely toward you than the moments such as contendeley dining and peacefully taking the subway. Illusory correlation plays a critical role in stereotyping. Stereotyping is the generalizations about a group of people where each member of the group is assumed to have the same traits. Hamilton & Rose (1980) conducted a study that included three experiments, examining illusory correlations and social stereotypes. The sample group included 73 male and 77 female high school and undergraduate students and adults. In the first experiment, the participants were required to read multiple sentences, and the sentences had specific adjectives to describe different professions which therefore gave that profession a specific trait. For example, the adjectives, thoughtful and wealthy, were used to describe doctors, and the adjectives, enthusiastic and talkative, were used to describe salesmen. Other non-stereotypical trait adjectives such as boring, clever, and demanding were included as well. In the second experiment, the adjectives used in the sentences either went along with stereotypic beliefs about the different professions or didn’t relate to the profession’s stereotype. In the third study, traits either didn’t go along with or didn’t relate to a profession’s stereotype. The participants then made estimations on how often had each adjective described members from each of the different professions. The entire study showed systematic biases in the discernments of the participants. The perceived correlation between traits and professions was more congruent with known stereotypical beliefs than the true correlation. The results revealed a cognitive bias in the process of learning new information regarding social groups, influenced by known stereotypes. This study displays stereotypical thinking. It shows that illusory correlations are precipitated when two uncommon events happen together. These observer’s awareness towards these events are enhanced. Therefore memories of the events become ingrained into the observer’s mind, allowing the observer to easily remember the events. As the memory is more easily retrieved, the more it influences the thinking process. Illusory correlations can result in remembering information that confirms the expected relationship.