Safety in Numbers: Why the Mere Physical Presence of Others Affects Risk-taking Behaviors

Eileen Y. Chou*, Loran F. Nordgren

*Corresponding author for this work

Research output: Contribution to journalArticle

7 Scopus citations


As social mammals, being in a group signals a state of relative security. Risk-taking behavior in other social mammals formed the basis for our prediction that the mere physical presence of others, absent any social interaction, would create a psychological state of security that, in turn, would promote greater risk-taking behavior. We investigated whether, why, and when the mere physical presence of others affects risk-taking behaviors in three contexts: acceptance of greater financial volatility, attitudes toward risky gambles, and actual gambling behaviors. Results indicate that people in the mere physical presence of others make riskier decisions than people making identical decisions alone, and that feelings of security were the psychological mechanism behind this effect. Our results also suggest that the effect is contingent on whether people are surrounded by others who belong to the same social group. A meta-analysis across all studies presented in this research reveals a highly reliable mere-presence effect. Together, these results demonstrate that the mere physical presence of others can have a potent impact on risk-taking behaviors.

Original languageEnglish (US)
Pages (from-to)671-682
Number of pages12
JournalJournal of Behavioral Decision Making
Issue number3
StatePublished - Jul 2017



  • mere physical presence
  • psychological security
  • risk-taking behavior
  • social group

ASJC Scopus subject areas

  • Decision Sciences(all)
  • Arts and Humanities (miscellaneous)
  • Applied Psychology
  • Sociology and Political Science
  • Strategy and Management

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