Apocalypse now: Thoughts about human extinction under mortality salience increase death-thought accessibility but reduce worldview defense

Death Studies ISSN: 0748-1187 (Print) 1091-7683 (Online) Journal homepage: www.tandfonline.com/journals/udst20 Apocalypse now: Thoughts about human extinction under mortality salience increase death-thought accessibility but reduce worldview defense Michael Rihs, Flurina L. Brodwolf & Fred W. Mast To cite this article: Michael Rihs, Flurina L. Brodwolf & Fred W. Mast (15 Apr 2025): Apocalypse now: Thoughts about human extinction under mortality salience increase death-thought accessibility but reduce worldview defense, Death Studies, DOI: 10.1080/07481187.2025.2469137 To link to this article: https://doi.org/10.1080/07481187.2025.2469137 © 2025 The Author(s). Published with license by Taylor & Francis Group, LLC. View supplementary material Published online: 15 Apr 2025. Submit your article to this journal Article views: 857 View related articles View Crossmark data Citing articles: 1 View citing articles Full Terms & Conditions of access and use can be found at https://www.tandfonline.com/action/journalInformation?journalCode=udst20 Death StuDieS Apocalypse now: Thoughts about human extinction under mortality salience increase death-thought accessibility but reduce worldview defense Michael Rihs , Flurina L. Brodwolf , and Fred W. Mast institute of Psychology, university of Bern, Bern, Switzerland ABSTRACT Various threats (e.g., climate change, nuclear wars, pandemics) pose the risk of human extinction. This represents a threat to human cultures and should result in effects similar to mortality salience (MS). At the same time, thoughts about human extinction reduce the belief in a long-lasting culture. This conflicts with the striving for symbolic immortality as a strategy to buffer MS. To investigate how thoughts about human extinction affect terror management, participants were presented with either an apocalyptic, destructive, or neutral video in combination with a manipulation of MS. Participants reported highest death-thought accessibility when watching the apocalyptic video under MS. However, worldview defense was decreased after watching the apocalyptic video under MS. These findings point to a dissociation between proximal and distal defense mechanisms: Thoughts about human extinction increase proximal defenses under MS, but they undermine the strive for symbolic immortality by worldview defense as distal defenses. Threats like the COVID-19 pandemic, escalating international tensions, and climate change pose a danger to human survival. The “Doomsday Clock” illustrates this danger and warns the public about the risk of man-made catastrophes. As of 2025, the clock stands at 89 seconds to midnight – its closest proximity to doomsday ever recorded (Bulletin of the Atomic Scientists, 2025, January 28). Consequently, thoughts about human extinction are no longer mere speculation. Indeed, a recent poll revealed that 73% of British citizens expect humanity to go extinct (Pauly, 2022). Despite the widespread belief in human extinction, only little research has investigated psychological responses to thoughts about human extinction. Terror management theory (TMT; Pyszczynski et al., 2015) offers a framework to investigate these effects. According to TMT, individuals who experience an increased awareness of one’s mortality – referred to as mortality salience (MS) – typically employ defense mechanisms like worldview defense or self-esteem striving (Arndt etal., 1997; Jonas & Fischer, 2006; Rosenblatt et al., 1989). Thoughts about human extinction might elicit defense mechanisms that are similar to those of MS. Research has shown that responses to MS unfold in proximal and distal defense mechanisms (see Kosloff et al., 2019). Proximal defenses focus on suppressing death-related thoughts under MS, which ironically leads to increased death-thought accessibility (DTA; Pyszczynski et al., 1999). This effect draws on findings from Wegner’s (1994) ironic process theory. In his research, Wegner has shown that attempts to suppress thoughts paradoxically enhance their accessibility. Initially, DTA is low under MS. However, cognitive load or distraction prevent suppression of death-related thoughts and increase DTA (Arndt etal., 1997; Greenberg et al., 1994). The increase in DTA under MS not only occurred in standardized laboratory settings but also during the COVID-19 pandemic, indicating that the awareness of mortality was higher during the pandemic (Fairlamb, 2022). However, the threat of the pandemic might have prompted thoughts not only about one’s mortality but also about human extinction. These thoughts about human extinction could have intensified the suppression of death-related thoughts. To investigate if thoughts about the extinction of humanity also increase DTA, more experimental research is needed. © 2025 the author(s). Published with license by taylor & Francis Group, LLC. CONTACT Michael Rihs [email protected] institute of Psychology, university of Bern, Fabrikstrasse 8, Bern 3012, Switzerland. Supplemental data for this article can be accessed online at https://doi.org/10.1080/07481187.2025.2469137. this article has been corrected with minor changes. these changes do not impact the academic content of the article. https://doi.org/10.1080/07481187.2025.2469137 this is an Open access article distributed under the terms of the Creative Commons attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. the terms on which this article has been published allow the posting of the accepted Manuscript in a repository by the author(s) or with their consent. 2 M. RIHS ETAL. To reduce DTA, individuals under MS respond with distal defenses (Pyszczynski et al., 1999). Distal defenses bolster the cultural anxiety buffer, consisting of an individual’s cultural worldview and self-esteem (Pyszczynski et al., 2015). Cultural worldviews integrate the norms endorsed by a particular culture and they provide meaning in life (Miller & Massey, 2019). Individuals defend these cultural worldviews as a distal response to MS (e.g., Greenberg etal., 1990; Rosenblatt etal., 1989). For example, Arndt etal. (1997) demonstrated that participants under MS showed a pro-nationalistic bias to defend their cultural worldviews. Furthermore, this worldview defense reduced the elevated DTA, which had emerged during proximal defenses. As DTA only increases after a delay, cultural worldview defense also occurs delayed to MS (Greenberg et al., 1994). Since cultural values differ among individuals, the distal response to MS can vary. For example, individuals who emphasize materialism show higher materialistic consumption under MS, while those who emphasize pro-environmental values show higher ecologically mindful consumption (Akil etal., 2018). Responses to MS vary not only depending on the cultural worldviews, but they are also influenced by individual differences in self-esteem. Individuals with high self-esteem perceive themselves as valuable members of their own culture, and this provides a buffer against existential threats by affirming one’s values within a cultural context. As a result, individuals with high self-esteem show reduced proximal and distal defense mechanisms under MS (Harmon-Jones et al., 1997; Rihs et al., 2022). Since the cultural anxiety buffer copes with existential concerns by providing meaning in life, threats to this buffer result in a similar existential threat as MS (Kosloff etal., 2019). Threatening an individual’s self-esteem or cultural worldview – for instance by exposure to contradicting worldviews – increases both DTA and worldview defense without MS (Hayes etal., 2008; Schimel et al., 2007). Buildings also hold profound significance for the cultural anxiety buffer since they represent cultural symbols. Watching the depiction of destroyed buildings – for instance, the burning World Trade Center – represents a cultural threat and elicits higher worldview defense (Vail et al., 2012). Thus, threats to an individual’s culture result in defense mechanisms similar to MS. Thoughts about human extinction pose a similar threat to the cultural anxiety buffer and could therefore result in proximal and distal defense mechanisms. Cultural worldviews are an integral part of TMT because they offer a path to symbolic immortality (Pyszczynski et al., 2015). Individuals achieve symbolic immortality through a lasting legacy of symbols, ideas, or cultural contributions. This legacy can manifest through artistic creations, memories held by others, or the continuation of one’s genetic lineage (Lifton & Olson, 1991). Multiple studies showed a striving for symbolic immortality under MS, such as higher desire for fame (Greenberg et al., 2010) or higher desire for offspring (Fritsche et al., 2007; Wisman & Goldenberg, 2005). These reactions to MS allow for a lasting legacy, which symbolically outlives an individual’s death. Potential thoughts about human extinction, however, conflict with the strive for symbolic immortality. When humanity goes extinct, there is no future generation that will outlast an individual’s death. Consequently, no one will engage with one’s cultural achievement, and – due to the lack of existential significance – symbolic immortality becomes meaningless. Thus, reminders of human extinction might inevitably reduce the value of symbolic immortality and thereby reduce distal defenses like worldview defense. This connection between symbolic immortality and worldview defense was shown in research by Scott etal. (2021). Individuals under MS showed higher worldview defense when they believed that their nation will continue to exist. This finding suggests an association between distal defenses under MS and the expected longevity of a culture. Thoughts about human extinction constrain symbolic immortality, and this is the reason why they could decrease worldview defense under MS. In the present study, we investigated how thoughts about human extinction unfold in the framework of TMT. We manipulated both MS and thoughts about human extinction. Widely discussed threats to humanity – for instance, global pandemics, armed conflicts between nations, or climate change – are unsuitable because we expected participants to hold confounding preexisting opinions. To avoid this, we used cosmic gamma rays as a rather unknown and less politically charged threat to induce thoughts about human extinction. We investigated the potential threat of cosmic gamma rays to human extinction and explored these effects in combination with MS (distal and proximal defenses). Potential connections to self-esteem were also analyzed since self-esteem buffers the effects of MS (e.g., Harmon-Jones etal., 1997). Method Participants The sample comprised 177 German-speaking students who participated in an online study in DEATH STuDIES 3 exchange for course credits. Thirty-five participants were excluded because they did not spend enough time on the corresponding survey page to fully view the thought-inducing video described below. Additional nine participants were excluded because they reported high knowledge about the topics which should prime thoughts about human extinction (see Results). The final dataset comprised 133 participants, including 115 women (86.5%) and 18 men (13.5%) with a mean age of 21.8 years (SD = 2.7 years). The study was reviewed and approved by the Ethics Committee of the Faculty of Human Sciences of the authors’ institution (application number 2019-10-00005). Design A 2 × 3 multivariate between-subjects design was conducted. The independent variables were MS (MS – control) and priming of different apocalyptic scenarios indicating human extinction by different videos (apocalyptic – destructive – neutral). The dependent variables were participants’ worldview defense and participants’ DTA. To check whether the different videos affected participants’ attitudes about human extinction, a manipulation check was conducted by rating the probability of survival chances of the scenario depicted in the video. We also measured participants’ positive and negative affect to ensure equality of affect across the conditions, since MS typically does not affect self-reported affect (see Burke et al., 2010). Materials Mortality salience MS was induced following a standard procedure used in previous studies (e.g., Arndt et al., 1997). Participants were asked to “please briefly describe the emotions that the thought of your own death arouses in you” and to “jot down, as specifically as you can, what you think will happen to you as you physically die and once you are physically dead”. Participants in the control condition were asked comparable questions concerning a tooth root treatment: “Please briefly describe the emotions that the thought of a tooth root treatment arouses in you” and “jot down, as specifically as you can, what you think will happen to you as you undergo a tooth root treatment”. This topic for control groups was also used in other studies (e.g., Rihs etal., 2022) and should tend to be negative without reminding of death. Priming human extinction A series of three animated educational videos was created to introduce distinct probabilities about potential threats of human extinction through gamma-ray bursts – an astrophysical phenomenon arising, for instance, from the collapse of stars into black holes. The videos informed about the universe, the solar system, galaxies, and cosmic rays. The apocalyptic video highlighted gamma-ray bursts as a threat, capable of destroying Earth and its inhabitants within moments. Conversely, the destructive video explained the low probability of this event and suggested that if a gamma-ray burst did strike Earth, only a portion of the planet would be affected, increasing the likelihood of survival. Both versions employed identical imagery, depicting the striking of Earth by a gamma-ray burst and the subsequent destruction of iconic cultural buildings (e.g., Eiffel Tower, Tower of Pisa). Prior research has demonstrated that images of destroyed buildings also result in terror management (Vail etal., 2012). Thus, potential effects of the apocalyptic and the destructive video might also be the result of watching or being reminded of destroyed buildings. Therefore, a neutral video was also included which mirrored the apocalyptic and destructive video in all aspects except the gamma-ray burst segment. Here, the neutral video explained cosmic radiation without illustrating destruction, thereby showing no threats at all. The respective material can be found on the associated OSF repository (see Data Availability Statement). Death-thought accessibility A word completion task used by Fritsche etal. (2007) was used to measure DTA. Participants were asked to fill out a list of 24 different word completion items. For six items, a solution with both death-related and neutral words is possible (e.g., the item “GRA_” can be solved as the German translation of “grave” – “GRAB” – or neutrally as the German translation of “grey” – “GRAU”). Like in previous studies (e.g., Greenberg etal., 1994), an individual’s DTA score was calculated by adding up the number of death-related answers. Worldview defense To evaluate participants’ worldview defense, two short texts were created from the perspective of a foreign person who either praised or criticized the Swiss culture. The texts are similar to other materials used to measure worldview defense (e.g., Arndt etal., 1997). Both texts are evaluated using five questions about the author of the short texts (e.g., Arndt etal., 1997). 4 M. RIHS ETAL. The questions are “How much do you like this person?”, “How intelligent do you think this person is?”, “How knowledgeable do you think this person is?”, “How much do you agree with this person’s opinion of Switzerland?”, and “From your point of view, how true is this person’s opinion of Switzerland?”. Participants answered all questions using a 9-point Likert scale ranging from 1 (“not at all”) to 9 (“absolutely”). Answers to the five questions were summed up for both texts. Based on the methods used in previous studies (Arndt et al., 1997), participants’ worldview defense was calculated by subtracting the sum of the negative text from the sum of the positive text. Higher scores indicate a higher sympathy for the text and the author of the culture-praising text. Rosenberg Self-Esteem Scale To measure participants’ self-esteem, the German version of the Rosenberg Self-Esteem Scale was used (von Collani & Herzberg, 2003). Participants rated 10 different statements (e.g., “I take a positive attitude toward myself.”) using a 4-point Likert scale ranging from 0 (“Does not apply at all”) to 3 (“Fully applies”). Positive and Negative Affect Schedule The German version of the Positive and Negative Affect Schedule (PANAS; Breyer & Bluemke, 2016) was used to measure participants’ positive and negative affective state. The PANAS measures positive and negative affect separately by 20 different affective states. Participants rated the extent to which they felt these affective states at the moment using a 5-point Likert scale ranging from 1 to 5 (“Very slightly or not at all”, “A little”, “Moderately”, “Quite a bit”, “Extremely”). Procedure Participants engaged in an online questionnaire-based study. To prevent any influence of death-related thoughts, participants were provided with the subsequent cover story: The research investigates the interplay of personality traits and learning effectiveness through educational videos. Consequently, participants were informed that they will view a video, but specifics about its content were withheld before the study began. At the beginning, participants responded to demographic questions and the Rosenberg Self-Esteem Scale. Afterward, either MS was induced by letting participants answer two open questions about death, or they answered two similar questions about a tooth root treatment. Participants then watched one of the three videos. Subsequently, participants completed the PANAS to check for affective differences after the priming and to delay the measurement of the dependent variables. Since the effects of MS are most pronounced after 7 to 20 minutes (Burke et al., 2010; Greenberg et al., 1994), a word-search task was included as a second delay task. For this, participants were asked to find 12 words in a letter matrix within 3 minutes. Following this, the word completion task was administered to measure DTA. Afterward, participants read and evaluated the two opposing texts to measure worldview defense in counterbalanced order. To evaluate the manipulation’s efficacy, participants estimated the likelihood of three events on a visual analog scale from 0% to 100%. The questions were “What is the probability that the Earth will be struck by a gamma-ray burst within the next thousand years?”, “If the Earth is struck by a gamma-ray burst: What is the chance of survival for a single person?”, and “If the Earth is struck by a gamma-ray burst: What is the chance of survival for the entire human race?”. Subsequently, participants rated the video’s accuracy, their familiarity with the video’s subject matter, and their comprehension of gamma rays in general using a 7-point Likert scale ranging from 1 (“extremely poor”) to 7 (“extremely good”). Results Data analysis Data was analyzed using R (R Core Team, 2023) and RStudio (Posit Team, 2023). An alpha level of .05 was utilized for all statistical tests. Table 1 gives an overview of the sample across all conditions. Worldview defense A linear regression was performed to predict worldview defense by MS, video, and self-esteem. For video, two contrasts were established: The first contrast compared the apocalyptic against the neutral video, while the second contrast compared the apocalyptic with the destructive video. The results indicated a statistically significant model, R2 = .15, F(11, 121) = 1.94, p = .040. The predicted regression lines are shown in Figure 1 and a full depiction of all regression coefficients is given in Table 2. In comparison to the apocalyptic video, exposure to the neutral video was associated with increased worldview defense, b = 18.46, t(121) = 2.81, p = .006, whereas exposure to the destructive video led to decreased worldview defense, b = −13.99, t(121) = −2.57, p = .011. Meanwhile, the impact of MS on worldview defense did not reach significance, b = 11.47, t(121) = 1.79, DEATH STuDIES 5 p = .075. However, there was an interaction between MS and video. This interaction was evident for both the contrast with the neutral video, b = −22.28, t(121) = −2.47, p = .015, and the contrast with the destructive video, b = 18.57, t(121) = 2.18, p = .031. Further analysis of estimated marginal means for this interaction revealed that after viewing either the neutral video, M = 8.63, SE = 1.57, t(121) = 5.50, p < .001, or the destructive video, M = 8.26, SE = 2.06, t(121) = 4.01, p < .001, individuals exposed to MS reported higher scores in worldview defense. In contrast, those who watched the apocalyptic video, M = 4.96, SE = 2.06, t(121) = 2.41, p = .017, displayed lower levels of worldview defense. In the control group, participants exhibited reduced worldview defense after exposure to the neutral, M = 5.60, SE = 2.02, t(121) = 2.77, p = .007, or destructive video, M = 4.19, SE = 1.82, t(121) = 2.30, p = .023, while reporting elevated worldview defense following the apocalyptic video, M = 7.51, SE = 1.86, t(121) = 4.04, p < .001. Furthermore, high self-esteem was associated with stronger worldview defense, b = 5.22, t(121) = 2.87, p = .005. Notably, a significant three-way interaction emerged between self-esteem, MS, and videos. This interaction was evident in relation to both the neutral video, b = 9.83, t(121) = 2.43, p = .016, and the destructive video, b = −9.99, t(121) = −2.57, p = .011. In the case of the neutral video, this effect was driven by individuals with low self-esteem who were exposed to the neutral video: Participants in the control group exhibited lower levels of worldview defense compared to those under MS, MDifference = −11.57, SE = 4.16, t(121) = −2.78, p = .032. However, no other comparisons reached statistical significance. Table 1. information about the sample split for all conditions. Neutral Video apocalyptic Video Destructive Video Variable Control MS Control MS Control MS Number of Participants 20 31 23 18 23 18 Gender 17 women and 3 men 26 women and 5 men 20 women and 3 men 15 women and 3 men 21 women and 2 men 16 women and 2 men age M = 20.70 SD = 1.42 M = 21.61 SD = 2.40 M = 22.70 SD = 4.14 M = 22.00 SD = 2.20 M = 21.39 SD = 2.43 M = 22.33 SD = 2.70 Self-esteem M = 2.25 SD = 0.51 M = 2.14 SD = 0.55 M = 1.96 SD = 0.73 M = 2.13 SD = 0.41 M = 2.12 SD = 0.66 M = 2.08 SD = 0.61 accuracy of the Video M = 5.00 SD = 0.86 M = 4.61 SD = 1.09 M = 5.04 SD = 1.11 M = 5.44 SD = 0.78 M = 5.13 SD = 1.10 M = 5.11 SD = 0.83 Knowledge about the Video M = 3.30 SD = 1.26 M = 2.84 SD = 1.29 M = 3.17 SD = 1.40 M = 3.61 SD = 1.04 M = 3.17 SD = 1.27 M = 3.11 SD = 0.96 Knowledge about Gamma Rays M = 1.10 SD = 0.31 M = 1.26 SD = 0.44 M = 1.35 SD = 0.49 M = 1.33 SD = 0.49 M = 1.22 SD = 0.42 M = 1.28 SD = 0.46 Figure 1. Regressions of self-esteem on worldview defense by condition and video. 6 M. RIHS ETAL. To ensure the validity of the effect of MS on worldview defense, a separate analysis was performed, focusing solely on the neutral video. The findings indicated that both MS, b = 33.75, t(47) = 2.77, p = .008, and self-esteem, b = 13.88, t(47) = 3.22, p = .002, were associated with increased worldview defense. Furthermore, MS and self-esteem interacted with each other, b = −14.54, t(47), = −2.71, p = .009. Participants with low self-esteem exposed to MS reported higher worldview defense (M = 8.94, SE = 2.34) compared to those in the control group, M = −0.87, SE = 3.38, MDifference = −9.80, SE = 4.11, t(47) = −2.39, p = .021. No significant differences were found for participants with medium, MDifference = −2.05, SE = 2.79, t(47) = −0.73, p = .466, or high self-esteem, MDifference = 5.70, SE = 3.89, t(47) = 1.47, p = .149. Death-thought accessibility A 2 × 3 factorial ANOVA was conducted to analyze participants’ DTA. The results indicated no significant main effect for either MS, F(1, 127) = 0.87, p = .352, or video, F(2, 127) = 0.83, p = .437. However, MS and video interacted significantly, F(2, 127) = 3.24, p = .042, ηp2 = .05. DTA scores increased due to MS after exposure to the apocalyptic video, MDifference = −0.61, SE = 0.28, t(127) = −2.20, p = .030. However, such an effect was not evident after watching the neutral, MDifference = −0.25, SE = 0.25, t(127) = −0.99, p = .327, or the destructive video, MDifference = 0.38, SE = 0.28, t(127) = 1.35, p = .178. Manipulation checks Knowledge about the video content Even though participants reported moderate knowledge about the contents of the videos (M = 3.17, SD = 1.23), they reported little knowledge about gamma-ray bursts (M = 1.26, SD = 0.44). Nine participants reported high knowledge about this topic – higher than 1.5*SD above the median – and were therefore excluded from the analysis. Participants perceived the video as accurate (M = 5.02, SD = 1.01). Probability ratings A 2 × 3 factorial ANOVA was performed on participants’ ratings of the three apocalyptic scenarios individually. Figure 2 depicts the likelihood ratings for the three questions. A significant main effect of video emerged for the reported likelihood of a gamma-ray burst hitting Earth, F(2, 127) = 9.11, p < .001, ηp2 = .13, the likelihood of an individual’s survival of this event, F(2, 127) = 15.94, p < .001, ηp2 = .20, and the likelihood of humanity’s survival of this event, F(2, 127) = 14.10, p < .001, ηp2 = .18. Compared to the neutral video, watching the apocalyptic video reduced the reported likelihood of a gamma-ray burst hitting Earth, MDifference = 23.52, SE = 5.91, t(127) = 3.98, p < .001, d = 0.85, the likelihood of an individual’s survival of this event, MDifference = 27.07, SE = 4.69, t(127) = 5.78, p < .001, d = 1.23, and the likelihood of humanity’s survival of this event, MDifference = 28.89, SE = 5.22, t(127) = 5.54, p < .001, d = 1.18. In contrast to the destructive video, the apocalyptic video only reduced the likelihood of humanity’s survival, MDifference = −13.84, SE = 5.46, t(127) = −2.54, p = .033, d = −0.56. An interaction between video and MS emerged for the reported likelihood of an individual’s survival of a gamma-ray burst, F(2, 127) = 3.89, p = .023, ηp2 = .06, as well as the likelihood of humanity’s survival, F(2, 127) = 4.73, p = .010, ηp2 = .07. An extensive description of these interactions and further pairwise comparisons can be found in the Supplemental Material. Table 2. Regression table for participants’ worldview defense score. 95% CI effect Estimate SE Lower Upper tdf p intercept −5.26 4.06 −13.30 2.78 −1.29 121 .198 Condition [Mortality Salience] 11.47 6.39 −1.19 24.12 1.79 121 .075 Video apocalyptic - Neutral 18.46 6.58 5.44 31.49 2.81 121 .006** apocalyptic - Destructive −13.99 5.45 −24.78 −3.20 −2.57 121 .011* Self-esteem 5.22 1.82 1.62 8.82 2.87 121 .005** Condition [Mortality Salience] * Video apocalyptic - Neutral −22.28 9.02 −40.13 −4.43 −2.47 121 .015* apocalyptic - Destructive 18.57 8.52 1.69 35.44 2.18 121 .031* Condition [Mortality Salience] * Self-esteem −4.71 2.91 −10.46 1.05 −1.62 121 .108 Video * Self-esteem apocalyptic - Neutral −8.66 2.89 −14.38 −2.94 −3.00 121 .003** apocalyptic - Destructive 7.37 2.45 2.52 12.21 3.01 121 .003** Condition [Mortality Salience] * Video * Self-esteem apocalyptic - Neutral 9.83 4.04 1.83 17.82 2.43 121 .016* apocalyptic - Destructive −9.99 3.88 −17.69 −2.30 −2.57 121 .011* DEATH STuDIES 7 Affect A 2 × 3 ANOVA was performed for participants’ positive and negative affect. Positive affect exhibited no significant differences in relation to MS, F(1, 127) < 0.01, p = .998, videos, F(2, 127) = 1.13, p = .327, or their interaction, F(2, 127) = 1.36, p = .259. Similarly, the analysis showed that negative affect did not vary significantly based on MS, F(1, 127) = 0.75, p = .389, videos, F(2, 127) = 0.71, p = .496, or the interaction between these factors, F(2, 127) = 2.22, p = .113. Lambert et al. (2014) demonstrated that the influence of MS was more evident on anxiety-related items and not on other types of unpleasant affect. Therefore, we conducted a 2 × 3 ANOVA for each item separately. A main effect of video emerged for the item “hostile”, F(2, 127) = 3.43, p = .035, ηp2 = .05, which was driven by more hostile feelings when watching the destructive compared to the neutral video, MDifference = −0.28, SE = 0.11, t(127) = −2.67, p = .023, d = −0.57. For the item “upset”, video and MS interacted, F(2, 127) = 5.88, p = .004, ηp2 = .08. Participants under MS felt more upset after watching the destructive video compared to both the neutral video, MDifference = −0.77, SE = 0.24, t(127) = −3.21, p = .005, d = −0.95, and the apocalyptic video, MDifference = −0.72, SE = 0.27, t(127) = −2.66, p = .024, d = −0.89. For all other items of the PANAS, there were no effects of MS, the videos, or an interaction of these two variables. Discussion Concerns about the future and the continuation of human existence have become a pivotal challenge. In this study, we investigated how thoughts about human extinction under MS affect proximal defense mechanisms – by means of DTA – and distal defense mechanisms – by means of worldview defense. To induce thoughts about human extinction, participants were Figure 2. Participants’ mean and standard deviations of the estimations of probabilities for the three different apocalyptic scenarios. 8 M. RIHS ETAL. exposed to videos explaining the threat of gamma-ray bursts – a topic with which participants were unfamiliar. The severity of this threat varied between the videos. The apocalyptic video highlighted the threat of this event to human extinction, the destructive video displayed the same destructive content but highlighted the possibility of surviving this event, and the neutral video did not discuss this threat. After watching these videos, participants differed in their estimates of surviving a gamma-ray burst hitting Earth, with the apocalyptic video resulting in the lowest perceived survival probability. The induced thoughts about human extinction resulted in a dissociation of proximal and distal defense mechanisms under MS. Reminders of human extinction proximally increased DTA but distally reduced worldview defense. The increase in DTA after reminders of human extinction under MS aligns with previous research showing increased DTA after MS and threats to cultural worldviews (Greenberg et al., 1994; Hayes et al., 2008). According to TMT, DTA increases due to automatic suppression of death-related thoughts (e.g., Greenberg et al., 1994; Kosloff et al., 2019). Therefore, the peak in DTA suggests that thoughts about human extinction under MS increase the need to suppress death-related thoughts. This effect is not the result of the mere exposure to destroyed civilizations, since watching the destructive video did not increase DTA under MS. Instead, thoughts about human extinction also pose a threat to cultural worldviews and symbolic immortality. This aligns with research showing increased DTA when confronted with comparable threats like the COVID-19 pandemic or watching images of destroyed buildings after a natural disaster (Fairlamb, 2022; Vail et al., 2012). Interestingly, while thoughts about human extinction increased proximal defense mechanisms under MS, they reduced distal defense mechanisms. Similar to earlier studies (e.g., Rosenblatt et al., 1989), MS increased worldview defense. However, participants exhibited reduced worldview defense when they watched the apocalyptic video under MS. The induced thoughts about human extinction mitigated the effect of MS on worldview defense. These results align with previous research showing a correlation between worldview defense and the expected longevity of a culture under MS (Scott et al., 2021). The current study extends these findings by demonstrating that reducing the expected longevity of a culture – implemented by thoughts about human extinction – also reduced worldview defense under MS. Cultural worldviews provide the possibility for symbolic immortality when people live up to the values of the respective culture (Pyszczynski et al., 2015). Under MS, worldview defense gives individuals an opportunity to live up to the values of their culture and it thereby provides a sense of symbolic immortality. Thoughts about human extinction, however, reduce the existential value of symbolic immortality by highlighting the possibility that no future generation will engage with one’s culture. Therefore, thoughts about human extinction reduce the strive for symbolic immortality under MS, resulting in less worldview defense. Recent research has cast doubts on the validity of the worldview defense hypothesis in TMT since multiple studies (Klein etal., 2022; Schindler etal., 2021; Treger et al., 2023) failed to replicate findings by Greenberg etal. (1994). However, research has shown that self-esteem moderates the effects of MS (Harmon-Jones etal., 1997; Rihs etal., 2022; but see Juhl & Routledge, 2014). Recent research by Lifshin etal. (2021) also demonstrated that symbolic immortality only partially mediates the relationship between self-esteem and DTA. This suggests that the buffering effect of self-esteem extends beyond symbolic immortality and encompasses additional factors, such as an enhanced sense of security stemming from the internalization of cultural worldviews (Becker etal., 2014). Consequently, potential effects of MS and thoughts about human extinction on worldview defense might be overshadowed by moderating effects of self-esteem. Therefore, we also investigated the effects of self-esteem in combination with MS and the induction of thoughts about human extinction. Worldview defense was associated with self-esteem, suggesting that individuals with low self-esteem have more potential to increase worldview defense. Therefore, the effects of MS and potential reminders of human extinction predominantly affected individuals with low self-esteem. Moreover, when we analyzed the data of participants who watched the neutral video, we were able to show that self-esteem moderated the effects of MS on worldview defense. The increase in worldview defense was only found for participants with low self-esteem. This aligns with previous research showing that participants with low self-esteem are more susceptible to MS (Harmon-Jones et al., 1997; Rihs et al., 2022). Therefore, it is crucial to include a measure of self-esteem in future research on TMT. Otherwise, the moderating role of self-esteem could overshadow the effect of MS on worldview defense. Although thoughts about human extinction increased DTA under MS, two anticipated effects were absent. First, the depiction of destroyed buildings, which represents a threat to the cultural anxiety buffer (Vail et al., 2012), did not affect DTA. This