title: Sick man walking: Perception of health status from body motion.
abstract: An ability to detect subtle signs of sickness in others would be highly beneficial, as it would allow for behaviors that help us avoid contagious pathogens. Recent findings suggest that both animals and humans are able to detect distinctive odor signals of individuals with activated innate immune responses. This study tested whether an innate immune response affects a person's walking speed and whether other people perceive that person as less healthy. 43 subjects watched films of persons who were experiencing experimental immune activation, and rated the walking individuals in the films with respect to health, tiredness, and sadness. Furthermore, the walking speed in the films was analyzed. After LPS injections, participants walked more slowly and were perceived as less healthy and more tired as compared to when injected with placebo. There was also a trend for the subjects to look sadder after LPS injection than after placebo. Furthermore, there were strong associations between walking speed and the appearance of health, tiredness, and sadness. These findings support the notion that walking speed is affected by an activated immune response, and that humans may be able to detect very early signs of sickness in others by merely observing their gait. This ability is likely to aid both a "behavioral immune system", by providing more opportunities for adaptive behaviors such as avoidance, and the anticipatory priming of biochemical immune responses.
authors: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Department of Psychology, Stockholm University, Stockholm, Sweden.
authors: T
authors: T
authors: Sundelin
authors: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden.
authors: B
authors: B
authors: Karshikoff
authors: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden.
authors: E
authors: E
authors: Axelsson
authors: Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden; Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden; Department of Medicine Solna and CMM, Karolinska Institutet and Karolinska University Hospital Solna, Stockholm, Sweden.
authors: C Olgart
authors: CO
authors: Höglund
authors: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm University, Stockholm, Sweden.
authors: M
authors: M
authors: Lekander
authors: Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden; Osher Center for Integrative medicine, Karolinska Institutet, Stockholm, Sweden; Stress Research Institute, Stockholm University, Stockholm, Sweden. Electronic address: john.axelsson@ki.se.
authors: J
authors: J
authors: Axelsson
mesh_terms: D000328:Adult; D005260:Female; D005684:Gait / Q000187:drug effects / Q000502:physiology*; D006304:Health Status; D006801:Humans; D055809:Illness Behavior / Q000187:drug effects / Q000502:physiology; D007600:Judgment; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D010465:Perception; D016138:Walking / Q000502:physiology*; D055815:Young Adult
chemical_list: D008070:Lipopolysaccharides
keywords: Behavioral immune system; Biological motion; Innate immunity; Sickness; Sickness avoidance