Since man began to use his reasoning capacity as a condition for his evolution, the idea was maintained that his gestures and attitudes were based on the logical and rational precept. From the moment it was understood that the individual s reasoning capacity is limited on complex and risky issues, the behavioral variable began to be inserted in numerous studies and theories on the decision process, identifying the existence and use of cognitive shortcuts (heuristics) in an attempt to solve complex problems. In this sense, this work tries to show how people are affected by heuristics and decision biases. In order to reach this goal, 144 people were part of a random sample that participated in a research that was intended to invite participants to make a decision or to express an opinion about situations that sought to identify the existence of errors of choices and individual personality traits.