Experiments published in 2008 used a standard way to test Terror Management Theory: asking participants to think about their own deaths, answering questions such as: "Briefly describe the emotions that the thought of your own death arouses in you." (A control group was asked to think about dental pain, something unpleasant, but not existentially threatening.)

TMT suggests that one response to thinking about death is to cling more strongly to the view that life has some wider meaning, so after their intervention they asked participants to indicate their agreement with statements such as: "Life has no meaning or purpose”, or “All strivings in life are futile and absurd”. From the answers they positioned participants on a scale of how strongly they felt life had meaning.

The responses were influenced by how prone people were to nostalgia. The researchers found that reminding participants of their own deaths was likely to increase feelings of meaninglessness, but only in those who reported that they were less likely to indulge in nostalgia. Participants who rated themselves as more likely than average to have nostalgic thoughts weren't affected by negative thoughts about their mortality (they rated life as highly meaningful, just like the control group).

Follow-up experiments suggest that people prone to nostalgia were less likely to have lingering thoughts about death, as well as less likely to be vulnerable to feelings of loneliness. Nostalgia, according to this view, is very different from a weakness or indulgence. The researchers call it a "meaning providing resource", a vital part of mental health. Nostalgia acts a store of positive emotions in memory, something we can access consciously, and perhaps also draw on continuously during our daily lives to bolster our feelings. It’s these strong feelings for our past that helps us cope better with our future.

Thanks to Jules Hall for suggesting the topic of nostalgia. If you have an everyday psychological phenomenon you'd like to see written about in these columns please get in touch @tomstafford or ideas@idiolect.org.uk.

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