Hundreds of studies have been conducted over the last four decades which support the central ideas of TMT. By reminding participants of death in various ways in the laboratory, ‘mortality salience’ studies have shown the broad range of ways in which death anxiety may drive human behaviour. For example, one fascinating early study examined the impact of thoughts of death on decision making among a sample of municipal court judges (Rosenblatt, Greenberg, Solomon, Pyszcynski, & Lyon, 1989). The judges were assigned to one of two conditions: In one condition, they were asked to write about their own death and the emotions that arise surrounding this, while those in the control condition were not. All participants were then given a brief description of a woman who had been arrested for prostitution (that is, an individual who was arguably deemed to have violated cultural worldviews regarding society norms around morality), and asked to assign her bond. The experiment revealed that the judges who had been reminded of death assigned an average bond of $455, relative to the $50 average bond assigned by judges in the control condition. That is, merely thinking of death for a few moments was sufficient to lead these municipal court judges, arguably pillars of reason and justice in our society, to assign a bond that was more than nine times greater than that considered fair and appropriate by their peers. Importantly, this all happened outside of their conscious awareness, suggesting that all of us are vulnerable to the effects of death anxiety without us even necessarily realising it.
Of course, the effects of death anxiety are not limited only to municipal decision making. Rather, hundreds of studies have shown that reminders of death drive a large array of human behaviours. These include spending behaviour, interracial conflict, aggression towards outgroup members (e.g., those with a different religious faith, or differing political views), driving behaviour, religious practice, and even sun tanning. A vast number of everyday behaviours appear to be driven by fears of death, building increasing support for Becker’s suggestion almost half a century ago that death anxiety lies at the heart of much of human action, including procreation, the creation of art, music, and literature, the pursuit of meaningful relationships, and striving for success in our workplaces and day to day lives.
The Dread of Death in Mental Health
While decades of TMT research have taught us much about the role of death anxiety in normal human behaviour, far less is known about the role of death fears in abnormal behaviour. Despite this, there is mounting evidence that death anxiety may, in fact, underlie many manifestations of mental health difficulties. The frequent appearance of the dread of death across the spectrum of mental health conditions and diagnostic categories has led researchers to argue that death anxiety should be considered a transdiagnostic construct, underpinning numerous disorders (Iverach, Menzies, & Menzies, 2014). Although some coping strategies to manage death anxiety may be adaptive, such as pursuing meaningful achievements or building relationships with others, fears of death may also drive unhelpful coping mechanisms, such as avoidance and other maladaptive behaviours. These behaviours, which are intended to protect the individual from their fears of death, may, in fact, play a central role in the development and maintenance of a variety of mental health conditions.
As a result, death anxiety has been implicated in a number of mental illnesses. For example, individuals with panic disorder commonly fear that they are suffering a heart attack, and may seek out medical expertise and appointments with cardiologists in an attempt to keep such worries at bay. Similarly, within illness anxiety, individuals will frequently check their body for signs of disease (including checking their own stools, urine, breasts, heartrate, and anything else that could forewarn death), interpret benign symptoms as threatening, and make repeated requests for medical tests. When turning our attention to the specific phobias, it becomes clear that most, if not all, of the most common phobias (e.g., spiders, heights, flying, water, snakes) centre on feared objects or situations that could directly result in death. Within agoraphobia and post-traumatic stress disorder, an experience of a life-threatening event, such as exposure to a physically threatening event or the loss of a loved one, often precedes the onset of either disorder. In obsessive compulsive disorder (OCD), patients will commonly report that their compulsive washing is done in a desperate effort to protect themselves from germs, and the resulting life-threatening illness that could occur. In a similar vein, those who engage in compulsive checking of locks, stovetops, and electric powerpoints likewise ascribe their efforts to attempts to prevent death via household invasion, fires, or electrocution. Death anxiety, alongside other existential concerns such as meaninglessness, has additionally been argued to play a role in depression.
Among all of the aforementioned disorders, scores on measures assessing fears of death have been shown to predict psychopathology, such that higher death anxiety has been proven to predict greater severity of symptoms. Similar results have also been found for conditions as diverse as alcohol use disorder, eating disorders, generalised anxiety disorder, body dysmorphic disorder, and separation anxiety disorder. However, while these proven correlations build support for the idea that death anxiety contributes to these disorders, experimental research is needed to show that the dread of death does indeed cause these conditions, rather than merely being associated with them.
To this end, although only a handful of TMT studies have explored the impact of death anxiety on abnormal or clinically-relevant behaviours, the results are promising. In support of the theorised role of death anxiety in phobias, one study found that mortality salience (in the form of asking participants to reflect on their own death) increased avoidance and perceived threat (e.g., the estimated likelihood that a given spider is dangerous) among spider phobics (Strachan et al., 2007). Interestingly, the same researchers found similar findings regarding social anxiety, a condition with less obvious connections to mortality. Thoughts of death led to participants high in social anxiety spending more time avoiding a subsequent group discussion. This added weight to the argument that death anxiety drives unhelpful avoidance behaviours which maintain anxiety. In a different study, reminders of death led women to restrict their consumption of fattening foods in a subsequent ‘tasting task’, and to perceive themselves as being further from their ideal thinness, suggesting the possible role of death anxiety in eating disorders (Goldenberg, Arndt, Hart & Brown, 2005).
Similarly, one recent study used the mortality salience design among a large sample of participants with OCD (Menzies & Dar-Nimrod, 2017). Reminders of death were found to lead participants to spend twice as long washing their hands, relative to those in the control condition, suggesting the central role of death anxiety in driving compulsive washing in OCD. Again, like the municipal court judges described above, these participants were completely unaware that the reminders of death they experienced earlier in the experiment had any effect on their washing behaviour.
Conclusion
Death anxiety is a central part of the human experience, and can be traced throughout 4000 years of human history. While our awareness of our own mortality is something that we must all grapple with, perhaps through bolstering buffers such as adherence to cultural worldviews and heightened self-esteem, this issue appears to plague some individuals more than others. In fact, increasing scientific evidence suggests that fears of death lie at the heart of a multitude of mental health conditions, and may drive numerous clinically-relevant behaviours. If this is indeed the case, what can we learn about confronting mortality from the tales of individuals who have been gripped by mental illness and the dread of death?