As defined in Lilienfeld's Psychology textbook, heuristics are mental shortcuts or rules of thumb. They help us make sense of our world. Essentially, what heuristics do is make things much easier for humans to grasp. With out them, humans would have too much to think about and could not handle all of the information that is obtained in a day. Although very helpful in making sense of what seems to be an easy thought to grasp, heuristics could also make humans oversimplify things. Shown as an example in the textbook, the fact that most people assume that Reno is northeast of San Diego when it is actually northwest of San Diego, is an example of a heuristic that is oversimplifying one's thoughts.