title: Why Do We Feel Sick When Infected--Can Altruism Play a Role?
abstract: When we contract an infection, we typically feel sick and behave accordingly. Symptoms of sickness behavior (SB) include anorexia, hypersomnia, depression, and reduced social interactions. SB affects species spanning from arthropods to vertebrates, is triggered nonspecifically by viruses, bacteria, and parasites, and is orchestrated by a complex network of cytokines and neuroendocrine pathways; clearly, it has been naturally selected. Nonetheless, SB seems evolutionarily costly: it promotes starvation and predation and reduces reproductive opportunities. How could SB persist? Former explanations focused on individual fitness, invoking improved resistance to pathogens. Could prevention of disease transmission, propagating in populations through kin selection, also contribute to SB?
authors.affiliation: Department of Psychology, College of Management Academic Studies, Rishon LeZion, Israel.
authors.forename: Keren
authors.initials: K
authors.lastname: Shakhar
authors.affiliation: Department of Immunology, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Guy
authors.initials: G
authors.lastname: Shakhar
mesh_terms: D000533:Altruism; D000818:Animals; D001294:Attitude to Health; D005075:Biological Evolution; D017281:Cost of Illness; D006801:Humans; D055809:Illness Behavior; D017053:Infection Control; D007239:Infections / Q000276:immunology / Q000503:physiopathology* / Q000635:transmission; D008954:Models, Biological; D012803:Sick Role