Fig. 1.

Study procedure. Participants came into the lab for two sessions, a minimum of 2 days apart at roughly the same time of day (see Methods). The first day began with monetary endowment, task instructions, and a basic comprehension quiz before the first (baseline) cortisol sample was taken (represented in the figure by a schematic salivary collection tube). After either undergoing the cold pressor test (CPT) or the lukewarm water control, participants gave a second salivary sample, waited 10 min for salivary cortisol levels to rise, and gave a third (pre-task) salivary sample. Participants then completed the risky decision-making task allowing estimation of risk attitudes (ρ, in green), loss aversion (λ, in red), and choice consistency (μ, in blue), after which they gave the fourth and final salivary sample, and completed a few basic debriefing questionnaires assessing their experience. The second day was identical to the first, except participants had an equal and independent chance of performing the CPT or lukewarm water control on each day. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of this article.)