The “Testerone Effect” on Decision-Making: How a Single Dose Can Cloud Judgment

Have you ever wondered whether higher testosterone levels push people toward making impulsive, gut-driven decisions rather than taking a moment to think things through?

A groundbreaking study published in Psychological Science examined this exact question. The researchers discovered that a single dose of testosterone actually impairs cognitive reflection in men, making them more likely to rely on intuitive—and often incorrect—first instincts.

The Experiment: Testing the CRT

To measure cognitive reflection (the ability to override an incorrect “gut response” and engage in deliberate, analytical thinking), researchers administered either a single topical dose of testosterone or a placebo to 243 young men.

Participants were then given the Cognitive Reflection Test (CRT), a famous set of trick questions designed to test mental discipline.

A Classic CRT Question:

“A bat and a ball cost $1.10 in total. The bat costs $1.00 more than the ball. How much does the ball cost?”

• The Intuitive Answer (Wrong): $0.10
• The Reflective Answer (Correct): $0.05 ($1.05 + $0.05 = $1.10)

What the Study Revealed

The results were striking:

• Fewer Correct Answers: Men who received the single dose of testosterone scored significantly lower on the Cognitive Reflection Test compared to those who received the placebo.
• Faster (and Rash) Responses: Participants in the testosterone group made faster decisions when giving incorrect answers, demonstrating a eagerness to go with their immediate gut reaction.
• Overconfidence: Despite making more errors, men in the testosterone group showed higher confidence in their incorrect answers.

Why Does Testosterone Affect Thinking This Way?

The researchers theorize that testosterone enhances status-seeking and dominant behaviors. From an evolutionary perspective, confidence and quick decision-making can project power, but in modern analytical environments, it can lead to costly errors.

Testosterone appears to reduce neural activity in regions of the brain responsible for self-monitoring and cognitive control, making people feel more certain of their first impressions without double-checking the facts.

Key Takeaways for Daily Life

Whether dealing with financial choices, strategic planning, or everyday problem-solving, understanding how hormones influence judgment can help you make better decisions:

1. Pause Before You Act: When faced with a complex decision, force a deliberate pause to bypass your initial gut instinct.
2. Double-Check Your Work: Don’t confuse feeling confident with being correct. Run through the logic or math explicitely.
3. Beware of High-Stress/High-Status Environments: Situations that trigger natural surges in testosterone (like competitive scenarios) may make you more prone to impulse-driven errors.

Read the Research

For the full methodology, data, and findings, read the original study by Nave et al.:

Single-Dose Testosterone Administration Impairs Cognitive Reflection in Men (Psychological Science)