In psychology, heuristics are thinking strategies that guide decisions and judgments that are made quickly. These quick judgments are fueled by learned and readily available information. For example, if a person observes a car speeding toward him, he jumps out of the way without needing to give it much logical thought. This is because the mind draws on past experiences or knowledge (using heuristics) to make the snap judgment to move.
There are several types of heuristics; one example is the availability heuristic. This mental shortcut relies on the most readily accessed examples that come to someone's mind when making a judgment, such as in the car scenario. The availability heuristic protects people from danger, but it can also lead to bias. For example, when purchasing a new vehicle, people may decide to go with the one they have heard the most about, but this may not be the most logical decision.
The representative heuristic is another example. This heuristic governs the thought process that involves making associations and comparisons to existing models. These comparisons can be useful for some problems, but this can also lead to the type of bias that results in people wrongly establishing cause and effect. For example, representative bias leads to wrongful stereotypes.