Money for microbes-Pathogen avoidance and out-group helping behaviour

Int J Psychol. 2018 Oct;53 Suppl 1:1-10. doi: 10.1002/ijop.12416. Epub 2017 Feb 23.


Humans have evolved various adaptations against pathogens, including the physiological immune system. However, not all of these adaptations are physiological: the cognitive mechanisms whereby we avoid potential sources of pathogens-for example, disgust elicited by uncleanliness-can be considered as parts of a behavioural immune system (BIS). The mechanisms of BIS extend also to inter-group relations: Pathogen cues have been shown to increase xenophobia/ethnocentrism, as people prefer to keep their societal in-group norms unaltered and "clean." Nonetheless, little is known how pathogen cues influence people's willingness to provide humanitarian aid to out-group members. We examined how pathogen cues affected decisions of providing humanitarian aid in either instrumental (sending money) or non-instrumental form (sending personnel to help, or accepting refugees), and whether these effects were moderated by individual differences in BIS sensitivity. Data were collected in two online studies (Ns: 188 and 210). When the hypothetical humanitarian crisis involved a clear risk of infection, participants with high BIS sensitivity preferred to send money rather than personnel or to accept refugees. The results suggest that pathogen cues influence BIS-sensitive individuals' willingness to provide humanitarian aid when there is a risk of contamination to in-group members.

Keywords: Behavioural immune system; Individual differences; Inter-group help; Pathogen cues.

MeSH terms

  • Adult
  • Blood-Borne Pathogens / isolation & purification*
  • Cost of Illness*
  • Female
  • Helping Behavior*
  • Humans
  • Immune System / metabolism*
  • Male
  • Middle Aged
  • Young Adult