The study aims to establish a clear causal link between testosterone and threat perception and behavioral responses to threat. Namely, the study focuses whether high levels of testosterone will cause an individual to exhibit increased physiological responses to threat (e.g., increased blood pressure, heart rate, and endocrine responses) and a decreased behavioral response (e.g., ignoring the threat, avoiding the threat, and postponing dealing with the threat). The threat in this study is a social threat involving public speaking, and is an outgrowth of previous research on the avoidance of health threats.

Participants in the study will receive either a single dose of 10g 1% testosterone topical gel or placebo the day prior to participating in the study. The day of the study, participants will provide saliva samples throughout the study to track testosterone and cortisol levels. Participants will be asked to complete the Trier Social Stressor Task, which includes having to give a 5 minute speech to a panel of judges. Participants will be given the opportunity to postpone giving their speech to an unspecified date. The study will focus on two types of responses to the threat of public speaking: behavioral and physiological. The behavior of interest will be participants desire to postpone dealing with the threat (it is hypothesized that those in the testosterone administration group will have an increased desire to postpone). The physiological responses include increased levels of cortisol and increased cardiovascular tone (it is hypothesized that the testosterone administration group will show an increased physiological response compared to the placebo group).

Inclusion Criteria:

• Male
• In good health
• Aged 18-35

Exclusion Criteria:

• Female
• Known carcinoma of the breast or prostate
• Known sensitivity to alcohol or soy products
• Preexisting cardiac, renal, or hepatic diseases
• Obesity
• Chronic lung diseases
• Cancer
• Use of anticoagulants
• Use of insulin or a history of diabetes
• Use of corticosteroids
• High levels of physical contact with women or children
• Preexisting liver problems