Your Stress Beliefs Are Changing Your Hormones

In 2013, Alia Crum at Stanford gave employees at a major financial firm two different videos to watch. Both groups were under serious stress. This was the 2008 economic crisis. Jobs were disappearing. Markets were collapsing. The stress was real and not going away.

One group watched a short video framing stress as debilitating. Your performance suffers. Your health suffers. Stress is something to reduce and avoid.

The other group watched a video framing stress as enhancing. Stress mobilizes energy. It sharpens focus. The research shows it can make you better.

Then Crum and her colleagues tracked both groups over the following weeks. The employees who watched the enhancing video showed better work performance and fewer health symptoms. Not because their stress load dropped. It didn't. Because they changed how they interpreted the stress they were already experiencing.

That's not a story about attitude. That's a story about biology.

What Crum Actually Measured

Crum wasn't interested in self-reports about feeling better. She wanted to see what happened inside the body when people changed their stress beliefs.

In a 2017 study with Carol Dweck, she took participants into a lab and gave them a "stress mindset" intervention — a three-minute video explaining research on the enhancing effects of stress. Then she put them through a standardized stress task and measured their hormonal response.

The participants who adopted a stress-is-enhancing mindset produced a different cortisol-to-DHEA ratio than the control group. More DHEA relative to cortisol. And if you've read the earlier pieces in this series, you know why that matters: the DHEA-dominant ratio is exactly what Blascovich and Mendes measured in challenge states versus threat states. It's associated with faster recovery, better cognitive performance, and neural growth.

A three-minute video shifted the hormonal profile of acute stress. Not by reducing cortisol. By raising DHEA alongside it.

That's beliefs becoming biology.

The Stress Mindset Measure

Crum developed the Stress Mindset Measure (SMM) to quantify where someone falls on the spectrum between "stress is enhancing" and "stress is debilitating." In her research, SMM scores predicted cortisol reactivity, performance under pressure, and health outcomes independently of how much stress someone was actually experiencing.

That last part is important. The same amount of stress hits differently depending on what you believe it's doing to you.

This connects directly to Keller and colleagues' 2012 study in Health Psychology, which tracked over 28,000 Americans for eight years. High stress plus the belief that stress is harmful was associated with a 43% increased risk of dying. High stress without that belief was not significantly associated with increased mortality. The belief was the variable that mattered, not the stress itself.

Crum's work shows the mechanism. It's not that believing stress is harmful just makes you feel bad. It changes your cortisol-to-DHEA ratio. It changes whether your body responds with a challenge profile or a threat profile. The belief shapes the physiology. The physiology shapes the outcome.

This Is Not Toxic Positivity

I want to be precise about what Crum is and isn't arguing, because this is where it's easy to go wrong.

She's not saying stress is always good. She's not saying you should pretend you love being overwhelmed. The framework isn't "think positive thoughts and your stress disappears."

The actual argument is more nuanced: stress responses contain both enhancing and debilitating elements, and which ones dominate depends partly on which ones you attend to. She calls this the "stress-as-resource" approach. You're not denying the stress. You're choosing what you notice about it.

In 2020, Crum and colleagues proposed what they call the "synergistic mindsets" model. They found that combining a stress-is-enhancing mindset with a growth mindset produced compounding benefits that neither mindset delivered alone. The two reinforce each other. If you believe challenges build capability AND you believe your stress response is helping you meet the challenge, something different happens than if you only have one or the other.

This also connects back to what Jeremy Jamieson at Harvard showed with GRE performance. Students who were told their anxiety was helping them scored better on practice tests and significantly better on the actual GRE months later. Alison Wood Brooks at Harvard followed that up showing that people who reappraised their pre-performance anxiety as excitement performed better on singing tasks, math problems, and public speaking than people who told themselves to calm down.

Same arousal. Different label. Different outcome.

The Mechanism Is Real

Here's what I keep coming back to as someone who spends a lot of time thinking about systems. The stress response isn't random. It's a resource allocation system. When activated, it decides what to do with the energy and hormones it generates.

Whether that allocation goes toward a challenge response (more DHEA, cardiovascular efficiency, focused attention) or a threat response (threat-typical cortisol spike, defensive narrowing, performance suppression) depends partly on what the brain predicts about the situation. And what the brain predicts depends partly on what you believe.

Beliefs function as predictive signals. Your brain is constantly running predictions about what's coming and what it means. If your prior belief is "stress is damaging," your brain builds that into its threat assessment. It predicts damage. It responds accordingly.

If your prior is "stress is a resource," your brain builds that in too. It predicts that the physiological response is functional. It activates the challenge profile. Which actually is more functional.

The belief doesn't override the biology. It shapes it.

What a Brief Intervention Can Do

The thing that still strikes me about Crum's research is how minimal the interventions are. Three-minute videos. Brief psychoeducation about the enhancing effects of stress. And these tiny inputs shift hormonal profiles, performance outcomes, and health trajectories.

That's not nothing. That's actually a huge claim. It means the leverage point isn't some massive psychological overhaul. It's a reframe that changes the signal your brain receives when stress activates.

You don't need to meditate for an hour a day. You don't need to eliminate the sources of stress from your life. You need to update the belief that stress is harming you, because that belief is part of what determines what stress actually does.

Jamieson's GRE work showed that a single sentence — "your arousal is helping you" — moved test scores. Brooks showed that two words — "get excited" instead of "calm down" — changed performance across multiple domains.

The neural architecture underlying the stress response is responsive to interpretation. That's the finding. Not "mindset is everything" in some vague self-help sense. But: your interpretation of your stress response is a causal input into what your stress response does.

Why This Took So Long to Figure Out

I think part of the reason Crum's work was surprising when it came out in 2013 is that we had a deeply embedded model of stress as a unidirectional threat. Stress damages health. More stress, more damage. Reduce stress, protect health.

That model fit the data from studies like those on chronic occupational stress and cardiovascular disease. It fit the intuition that relaxation is good and pressure is bad.

What it missed is that the stress response is more differentiated than that. There are different hormonal profiles within "stress." There are challenge and threat variants that produce opposite performance outcomes. And the brain's interpretation of the stressor — including the person's beliefs about what stress does — participates in determining which profile activates.

The Stanford Mind and Body Lab has spent the last decade building out the evidence base on this. The finding has replicated. The mechanism is reasonably well-understood. The intervention works.

You can change what stress does to you by changing what you believe stress does to you.

Sources

• Crum, A.J., Salovey, P., & Achor, S. "Rethinking stress: The role of mindsets in determining the stress response." Journal of Personality and Social Psychology, 104(4), 716-733 (2013).
• Crum, A.J., Akinola, M., Martin, A., & Fath, S. "The role of stress mindset in shaping cognitive, emotional, and physiological responses to challenging and threatening stress." Anxiety, Stress, & Coping, 30(4), 379-395 (2017).
• Keller, A., Litzelman, K., Wisk, L.E., et al. "Does the perception that stress affects health matter? The association with health and mortality." Health Psychology, 31(5), 677-684 (2012).
• Jamieson, J.P., Mendes, W.B., Blackstock, E., & Schmader, T. "Turning the knots in your stomach into bows: Reappraising arousal improves performance on the GRE." Journal of Experimental Social Psychology, 46(1), 208-212 (2010).
• Brooks, A.W. "Get excited: Reappraising pre-performance anxiety as excitement." Journal of Experimental Psychology: General, 143(3), 1144-1158 (2014).
• Blascovich, J. & Mendes, W.B. "Challenge and threat appraisals: The role of affective cues." In J.P. Forgas (Ed.), Feeling and thinking: The role of affect in social cognition (2000).

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Part of the Stress Paradox series. Previous: The Stress Response Has a Built-In Repair System (You're Probably Not Using It). Next: The Body That Builds Itself Stronger From Stress.