Political Behavior

, Volume 35, Issue 4, pp 753–776 | Cite as

Oxytocin and the Biological Basis for Interpersonal and Political Trust

  • Jennifer L. MerollaEmail author
  • Guy Burnett
  • Kenneth V. Pyle
  • Sheila Ahmadi
  • Paul J. Zak
Original Paper


Political scientists have documented the many ways in which trust influences attitudes and behaviors that are important for the legitimacy and stability of democratic political systems. They have also explored the social, economic, and political factors that tend to increase levels of trust in others, in political figures, and in government. Neuroeconomic studies have shown that the neuroactive hormone oxytocin, a peptide that plays a key role in social attachment and affiliation in non-human mammals, is associated with trust and reciprocity in humans (e.g., Kosfeld et al., Nature 435:673–676, 2005; Zak et al., Horm Beh 48:522–527, 2005). While oxytocin has been linked to indicators of interpersonal trust, we do not know if it extends to trust in government actors and institutions. In order to explore these relationships, we conducted an experiment in which subjects were randomly assigned to receive a placebo or 40 IU of oxytocin administered intranasally. We show that manipulating oxytocin increases individuals’ interpersonal trust. It also has effects on trust in political figures and in government, though only for certain partisan groups and for those low in levels of interpersonal trust.


Trust Government Biology Oxytocin 



This study was funded by a grant to Paul J. Zak from the John Templeton Foundation. We thank the anonymous reviewers and editors for helpful feedback.

The experiments comply with the current laws of the United States. All of the procedures were approved by the Institutional Review Boards of the universities involved.

Supplementary material

11109_2012_9219_MOESM1_ESM.pdf (62 kb)
Supplementary material 1 (PDF 62 kb)


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Copyright information

© Springer Science+Business Media New York 2013

Authors and Affiliations

  • Jennifer L. Merolla
    • 1
    Email author
  • Guy Burnett
    • 1
  • Kenneth V. Pyle
    • 1
  • Sheila Ahmadi
    • 3
  • Paul J. Zak
    • 2
  1. 1.School of Politics and Economics, Claremont Graduate UniversityClaremontUSA
  2. 2.Center for Neuroeconomic Studies and School of Politics and EconomicsClaremontUSA
  3. 3.Division of Endocrinology, Diabetes and HypertensionGeffen School of Medicine, UCLALos AngelesUSA

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