Negativity bias is the psychological phenomenon by which humans have a greater recall of unpleasant memories compared with positive memories. People are seen to be much more biased to the avoidance of negative experiences. They seem to behave in ways that will help them avoid these events. With this, humans are much more likely to recall and be influenced by the negative experiences of the past.

The capacity to put more weight on negative entities than positive ones likely evolved for an important reason: to keep us out of harm’s way. From the beginning of humanity is has been our most important survival skill to be able to stay away from or dodge danger. Knowing this survival technique, our brain has developed systems that make it hard for us to not notice danger and respond to it.

The concept of negativity bias is not new. The earlier research on this phenomenon led to the development of the prospect theory. The prospect theory evaluates the ways people make choices when there is a known risk. Both negativity bias and the derived prospect theory coincide with the idea that “people are much more likely to choose things based on their need to avoid negative experiences, rather than on their desire to get positive things”.

This phenomenon has recently been researched by psychologists Roy F. Baumister, Ellen Bratslavsky, Kathleen Vohs, and Catrin Finkenauer. These psychologists found that negative experience, or fear of bad events has a greater impact on people than do neutral or positive experiences. Their findings were published in 2001 and can be found in the Review of General Psychology in the article “Bad is Stronger than Good”. In the same year, another paper with almost exactly the same findings was published by Rozin and Royzman titled Negativity Bias, Negativity Dominance, and Contagion.

According to Rozi and Royzman, there are four ways in which humans and animals show to give greater weight to negative entities. These four aspects are negative potency, steeper negative gradients, negativity dominance, and negative differentiation. Negative potency is that negative entities are stronger than the equivalent positive entities. Steeper negative gradient means that the negativity of these negative events grows more rapidly with space or time than positive events. With negativity dominance, “combinations of negative and positive entities yield evaluations that are more negative than the algebraic sum of individual subjective valences would predict.” And finally, negative differentiation is that negative entities are more varied, yield more complex conceptual representations, and engage a wider response range. In their paper they seem to focus more on negativity dominance and on the idea that negative are more contagious than positive ones.