Lassitude: The emotion of being sick

Publication date: Available online 11 September 2019Source: Evolution and Human BehaviorAuthor(s): Joshua M. Schrock, J. Josh Snodgrass, Lawrence S. SugiyamaAbstractOur long co-evolutionary history with infectious agents likely began soon after the rise of the first single-celled organisms. This ongoing evolutionary arms race has generated complex host adaptations, many highly conserved, for resisting infection (e.g., innate and acquired immune systems, infection-sensitive developmental programs, sexual reproduction). A large body of evidence suggests that, in humans, pathogen-avoidance disgust is an emotion that motivates avoidance of cues associated with pathogens, thereby reducing infection. However, the question of whether there is an emotion that coordinates resistance to active infection has received less attention. We propose that lassitude is such an emotion. It is triggered by cues of active infection and coordinates the fight against infection by: (a) reducing energetically expensive movement to make more energy available to the immune system, (b) reducing exposure to additional infections and injuries that would compound the immune system's workload, (c) promoting thermoregulatory behaviors that facilitate immunity, (d) regulating food consumption to be beneficial for the host but detrimental to pathogens, and (e) deploying strategies that elicit caregiving behavior from social allies. Lassitude exhibits the core features of an emotion – it is triggered by cues o...
Source: Evolution and Human Behavior - Category: Psychiatry & Psychology Source Type: research