Emotional and cognitive responses toward mortality in life history strategy

Abstract

This dissertation, consisting of four papers, examines the effects of Life-History (LH) strategy and the current environment on emotional and cognitive responses toward mortality. Given the unavoidable death and limited lifespan, a fundamental problem faced by all living organisms is the resource allocation among various tasks associated with survival and reproduction. LH framework deals with the trade-offs in allocating finite time and resources over a life course, and an individual's LH manifestations remain flexible and sensitive to environmental signals. Due to the resource constraints and trade-offs among LH traits, humans fall along a continuum of slow to fast LH strategies. Across four studies, hypotheses are proposed to explain why specific LH predictors are more or less likely to influence the intensity of death fear and the cognitive judgment toward death-related decisions in a given environment. By employing different operations for the current environment (e.g., having participants report the perceived current environmental adversity and examining the participants under different ecological settings), the findings provide preliminary evidence for an association between LH strategy and fear-induced implicit avoidance of death and the perceived current environment moderates this association (Study 1). These findings are replicated in the natural settings of a death-salient versus non-death-salient environment (Study 2). Specifically, slow LH is associated with more intense death fear at lower than higher levels of mortality threats in individuals' current environment (Study 2). Further, based on the assumption that experiencing fear activates appraisal tendencies, influencing cognitive processes, judgment, and decision outcomes; hence, death fear is proposed as a mediator in the relationship between LH and subjective judgment of life-ending decisional scenarios (Study 3). The results suggest that slow LH is associated with more intense death fear, which in turn predicts the lower subjective justification of life-ending behaviors (Study 3). The findings further indicate that the fear of death partially mediates the relationship between slow LH and the subjective justification of life-ending behaviors (Study 3). Specifically, slow LH is negatively linked to the justification of end-of-life behaviors (Study 3 & Study 4), and the current environmental adversity moderates this relationship (Study 4). The interaction result suggests that current environmental harshness and unpredictability influence LH strategy in the same direction directly through interaction effects on the attitudes toward ending a life or by shaping LH strategy that regulates an individual's cognitive judgment (Study 4). The four papers extend the findings in the LH framework by demonstrating that the variations in emotional and cognitive processing regarding death information are contingent on LH strategy, and this association is influenced by the current environmental status that further calibrates an individual's LH manifestations.