The following two paragraphs relate to the concept of mortality salience and are quoted from “Terror Management and Anorexia Nervosa: Does Mortality Salience Increase Negative Perceptions of Women With Anorexia Nervosa?” by M. Katherine Kubota.
As primates, humans share many traits and behavioral characteristics with animals (Goldenberg, et al., 2001). However, a unique characteristic of humans appears to be an awareness of the inevitability of their own death. Terror management theory (TMT) (Greenberg, Pyszczynski, & Solomon, 1986) proposes that human awareness of death is at the root of a variety of social and cognitive behaviors. TMT theory states that in order to combat adverse feelings of anxiety over the awareness of one’s mortality (i.e. mortality salience) a cognitive process is actuated that reaffirms one’s socio-cultural world views. For example TMT researchers have found that priming individuals’ mortality salience leads individuals to embrace in-group members, reject out-group members, conform to cultural standards, shift to more favorable attitudes about their religion and seek out family members for support (Harmon-Jones, 1997). The shift to reaffirm ones socio-cultural world views is an attempt to deal with the anxiety of mortality salience. In essence, people seek the structure provided by society and culture, thus increasing their self-esteem and decreasing the uncomfortable thoughts associated with death (Greenberg, Pyszczynski, & Solomon, 1986).
After decades of research on TMT, one of the most consistent findings has been that increasing mortality salience results in increased liking of in-group members and rejection of different out-group members, (Goldenberg et al, 2001).
For a brief description of a typical mortality salience experiment, see this item on Jonah Lehrer’s blog, The Frontal Cortex.