Terror management theory (TMT) is about how we get through day-to-day life while still being aware of our own mortality. It's what keeps us from being consumed by our own fears and anxieties. I'd argue that good terror management practices are probably pretty essential to stay grounded during paranormal investigation and research as well.
I learned about this concept from the article "Fighting the future with the past: Nostalgia buffers existential threat", published in the Journal of Research in Personality, Volume 44, Issue 3, in 2010, which I mentioned yesterday.
According to the paper, the theory
asserts that people are able to live with relative psychological equanimity in the face of this awareness [of their own mortality] through investing and maintaining faith in psychological structures (e.g., self-esteem, relationships, cultural worldviews) that buffer death anxiety by imbuing life with meaning, order, significance, and self-transcendence.
Some of the same authors seemed to find that nostalgia helps with terror management in their 2008 study A blast from the past: The terror management function of nostalgia, published in the Journal of Experimental Social Psychology, Volume 44, Issue 1 .
They ran three different experiments, which suggest that nostalgia increased people's likelihood to find meaning in life and think about death less.
The abstract has a bit more info (if you can get through the academic-speak):
In Experiments 1 and 2, nostalgia proneness was measured and mortality salience manipulated. In Experiment 1, when mortality was salient, the more prone to nostalgia participants were, the more they perceived life to be meaningful. In Experiment 2, when mortality was salient, the more prone to nostalgia participants were, the less death thoughts were accessible. In Experiment 3, nostalgia and mortality salience were manipulated. It was found that nostalgia buffered the effects of mortality salience on death-thought accessibility.
As a sidenote, jeeze, I really struggle to understand academic writing. The level of obfuscation is wild, truly. I'm no academic, but I always think about How to Write a Lot: A Practical Guide to Productive Academic Writing by Paul J. Silvia, a bestselling book that explicitly tells academics not to write in dense and inaccessible ways. It's a great writing book and hopefully more people take his advice to heart.
Anyway, the article "Fighting the future with the past: Nostalgia buffers existential threat" talks about how nostalgia bolsters our self-concept. It also usually makes us feel more loved and protected and gives us "greater feelings of interpersonal competence and support." "Nostalgic reverie" also tends to be more positive than negative, and even the negative features redemption arcs.