title: Testosterone administration does not affect men's rejections of low ultimatum game offers or aggressive mood.
abstract: Correlative evidence suggests that testosterone promotes dominance and aggression. However, causal evidence is scarce and offers mixed results. To investigate this relationship, we administered testosterone for 48h to 41 healthy young adult men in a within-subjects, double-blind placebo-controlled balanced crossover design. Subjects played the role of responders in an ultimatum game, where rejecting a low offer is costly, but serves to destroy the proposer's profit. Such action can hence be interpreted as non-physical aggression in response to social provocation. In addition, subjects completed a self-assessed mood questionnaire. As expected, self-reported aggressiveness was a key predictor of ultimatum game rejections. However, while testosterone affected subjective ratings of feeling energetic and interested, our evidence strongly suggests that testosterone had no effect on ultimatum game rejections or on aggressive mood. Our findings illustrate the importance of using causal interventions to assess correlative evidence.
authors.affiliation: Departamento de Fundamentos del Análisis Económico, Universidad de Alicante, Spain. Electronic address: carlos.cueva@ua.es.
authors.forename: Carlos
authors.initials: C
authors.lastname: Cueva
authors.affiliation: Division of Brain Sciences, Department of Medicine, Imperial College London, UK.
authors.forename: R Edward
authors.initials: RE
authors.lastname: Roberts
authors.affiliation: Department of Psychiatry, University of Cambridge, UK; Cambridgeshire and Peterborough NHS Foundation Trust, Elizabeth House, Fulbourn Hospital, Cambridge, UK.
authors.forename: Tom J
authors.initials: TJ
authors.lastname: Spencer
authors.affiliation: Cambridgeshire and Peterborough NHS Foundation Trust, Elizabeth House, Fulbourn Hospital, Cambridge, UK.
authors.forename: Nisha
authors.initials: N
authors.lastname: Rani
authors.affiliation: Royal College of Psychiatrists, UK.
authors.forename: Michelle
authors.initials: M
authors.lastname: Tempest
authors.affiliation: Laboratory for Social and Neural Systems Research, Department of Economics, University of Zurich, Switzerland.
authors.forename: Philippe N
authors.initials: PN
authors.lastname: Tobler
authors.affiliation: John van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, UK.
authors.forename: Joe
authors.initials: J
authors.lastname: Herbert
authors.affiliation: Department of Economics, University of Minnesota, USA; Department of Physiology, Development and Neuroscience, University of Cambridge, UK. Electronic address: aldo.rustichini@gmail.com.
authors.forename: Aldo
authors.initials: A
authors.lastname: Rustichini
mesh_terms: D000328:Adult; D000339:Affect / Q000187:drug effects*; D000374:Aggression / Q000187:drug effects*; D003163:Competitive Behavior / Q000187:drug effects; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004644:Emotions / Q000187:drug effects; D000068957:Games, Recreational / Q000523:psychology*; D006801:Humans; D008297:Male; D009042:Motivation / Q000187:drug effects*; D012059:Rejection, Psychology; D011795:Surveys and Questionnaires; D013739:Testosterone / Q000008:administration & dosage* / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D013739:Testosterone
keywords: Aggression; Bargaining; Dominance; Neuroeconomics; Sex hormones