The significance of mortality is a term used to describe an individual’s awareness that one day he will die. This awareness can have a wide range of different effects on different people and is highly influenced by religion and other aspects of the worldview. Social psychologists often study the importance of mortality and how it affects the way people interact with one another. Awareness and contemplation of one’s own mortality has been shown to affect everything from political views to the opinions of members of different religious and ethnic groups. Some theories of social psychology suggest that almost all human action is motivated in some way by the direct or indirect awareness of one’s own mortality.

Terror management theory, or TMT, is a theory of social psychology that is based on the idea that fear of mortality motivates almost all human activities. Humans put themselves in a position of tremendous conflict because they have the instinct to try to avoid death at all costs and the intellectual capacity to recognize that attempts to avoid death will turn out to be futile. The prominence of mortality, consciously or unconsciously, drives humans to dedicate all their actions to avoiding death or distracting thought about mortality.

In many cases, an individual’s worldview, which contains political, religious, and other beliefs, provides a defense against the immediacy of mortality. Attacking these views, then, can cause a kind of vicarious importance of mortality, as the defenses against mortality are broken to some extent. This can motivate an individual to try to fortify his worldview against possible attacks, often to the point of irrational extremes.

Even if a person’s worldview is not attacked in some way, the importance of mortality has been shown to make people turn to their core beliefs for support. People who are reminded of their mortality tend to take their political, religious, or other views to even greater extremes. The strength of a person’s worldview is used as a psychological defense mechanism against death.

Many experiments in social psychology have been used to test the effects of mortality relevance. These tests usually start with researchers asking test subjects to complete some task that reminds them of mortality. A test subject, for example, might be asked to write a short narrative about his or her own death. After the test subject has completed the task, thus developing a certain level of mortality, he is asked to complete another task, such as expressing political opinions. Comparisons between control groups and groups of individuals forced to contemplate their own mortality indicated that awareness of mortality tends to make the person reinforce his particular worldview.