In a groundbreaking large-scale study set to redefine longstanding assumptions, researchers have meticulously analyzed the impact of testosterone on economic decision-making, delivering results that counter popular narratives previously fueled by smaller, less comprehensive investigations. This extensive research, conducted by a collaborative team from the Stockholm School of Economics (SSE) and Nipissing University in Canada, scrutinized whether acute administration of testosterone alters men’s inclination towards risk-taking, fairness, competitiveness, or generosity in economic contexts.
For decades, testosterone has been widely implicated as a hormonal catalyst fostering behaviors such as aggression, risk appetite, and competitive drive. However, prior studies examining these links rarely exceeded small sample sizes, often producing inconsistent or inconclusive findings. These early experiments suggested that elevated testosterone could predispose individuals to take economic risks, reject unfair transactions, or exhibit higher competitiveness. Recognizing the necessity for robust evidence, the investigative team designed a rigorously preregistered, randomized, double-blind clinical trial involving a considerably larger cohort than any preceding study.
The study enrolled approximately 1,000 healthy men aged 18 to 45, recruited between 2018 and 2023 across three Canadian centers. Participants were randomly assigned to receive either a single 11-milligram intranasal dose of testosterone or a placebo. The choice of intranasal delivery ensured rapid absorption and bioavailability of the hormone, allowing for a controlled examination of its acute effects. After a controlled 30-minute period to permit hormone uptake, subjects engaged in a battery of standardized economic decision-making tasks commonly endorsed in behavioral economics research.
These tasks were explicitly designed to quantify risk preferences, altruistic tendencies, fairness considerations, and competitive behavior. These nuances are critical to understanding the complex interplay between endocrine function and economic choices. Contrary to expectations built on prior smaller-scale research, the trial revealed no statistically significant differences in these behavioral domains between testosterone recipients and those administered a placebo. Across all nine principal outcomes assessed, testosterone did not meaningfully influence men’s economic preferences.
This revelation challenges a pervasive biological determinism narrative that assigns cortisol fluctuations a dominant causal role in modulating risk-taking and competitive behavior, at least within acute exposure frameworks. The lack of observed effect under controlled conditions suggests that transient testosterone elevations do not directly translate to altered economic decision-making. The authors emphasize that this result does not negate testosterone’s broader biological roles but rather calls for a nuanced understanding that recognizes the complexity of neuroendocrine and behavioral relationships, possibly moderated by dosage, chronicity, or individual differences.
Co-lead researchers Anna Dreber of SSE and Justin M. Carré of Nipissing University highlight the uniqueness and rigorous methodology of the present investigation. By preregistering hypotheses and analysis plans before data collection and employing a significantly larger subject pool, they mitigated many sources of bias that often color smaller studies. The departure from previous findings accentuates the critical value of replication and methodological soundness in behavioral endocrinology—a field historically vulnerable to publication bias and underpowered research.
The study also carefully delineates its scope, explicitly acknowledging limitations inherent to its design. Only a single testosterone dose was tested in a male-only cohort, leaving open questions about dose-response dynamics, gender differences, and potential long-term hormonal effects on economic cognition and social behaviors. These considerations pave avenues for future research that might employ stratified dosing regimes, longitudinal monitoring, and inclusion of female participants to fully elucidate testosterone’s role.
Moreover, the wide-reaching collaboration between multiple international institutions, including the University of Pennsylvania, University of the Fraser Valley, the University of Osaka, the University of Colorado, University College London, and Oakland University, underscores the global scientific effort invested in producing generalizable and trustworthy insights. Funding support from several prestigious bodies exemplifies the importance placed on clarifying hormonal influences on human economic and social conduct.
This study’s implications reverberate beyond endocrine research into economics, psychology, and public policy realms. It discourages simplistic biological explanations for complex human behaviors like financial risk-taking and fairness judgments, reinforcing the necessity of multidimensional frameworks that consider environmental, cognitive, and psychosocial factors alongside hormonal contributions.
In sum, this landmark investigation decisively rebuts the hypothesis that short-term testosterone surges modulate economic preferences in men. By harnessing the power of scale, rigorous design, and multifaceted analysis, the research sets a new standard in behavioral endocrinology, emphasizing that human economic behaviors are unlikely to be unilaterally driven by singular hormonal fluctuations. This refined understanding promises to inform future studies and interventions seeking to decode the biological underpinnings of economic decision making.
Subject of Research: People
Article Title: Investigating the effects of single-dose intranasal testosterone on economic preferences in a large randomized trial of men
News Publication Date: 23-Sep-2025
Web References: https://www.pnas.org/doi/10.1073/pnas.2508519122
References: Anna Dreber et al., Proceedings of the National Academy of Sciences (PNAS), DOI: 10.1073/pnas.2508519122
Image Credits: Juliana Wiklund (photo of Anna Dreber)
Keywords: Testosterone, economic decision-making, behavioral economics, risk-taking, competitiveness, generosity, hormonal effects, randomized controlled trial, intranasal administration, male behavioral study, replication, preregistration
