Mortality salience is a term used to describe an individual's awareness that, one day, he is going to die. This awareness can have a wide range of different effects on different people and is highly influenced by one's religion and by other aspects of one's worldview. Social psychologists often study mortality salience and how it affects how people interact with each other. Awareness and contemplation of one's mortality has been shown to affect everything from one's political views to one's opinions of members of different religious and ethnic groups. Some theories in social psychology suggest that almost all human action is somehow motivated by direct or indirect awareness of one's own mortality.
Terror management theory, or TMT, is a theory in social psychology that is built on the idea that fear of mortality motivates almost all human activity. Humans are placed in a position of tremendous conflict because they possess both the instinct to try to avoid death at all costs and the intellectual capacity to recognize that attempts to avoid death will ultimately be futile. Mortality salience consciously or subconsciously drives humans to devote all of their actions to avoiding death or to distract themselves from thinking about mortality.
In many cases, an individual's worldview, containing political, religious, and other beliefs, provides a defense against the immediacy of mortality. Attacking these views, then, can cause a kind of indirect mortality salience, as the defenses against mortality salience are broken down to some degree. This may motivate an individual to attempt to strengthen his worldview against potential attack, often to the point of irrational extremes.
Even if one's worldview is not somehow attacked, mortality salience has been shown to cause people to fall back to their fundamental beliefs for support. People who are reminded of their mortality tend to take their political, religious, or other views to greater extremes. The strength of one'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 salience. Such tests usually begin with researchers asking test subjects to complete some task that reminds them of mortality. A test subject may, for instance, be asked to write a short narrative about his own death. After the test subject has completed the task, thereby developing some level of mortality salience, he is asked to complete another task, such as expressing political views. Comparisons between control groups and groups of individuals forced to contemplate their own mortality has indicated that awareness of mortality tends to cause one to bolster his particular worldview.