Science of Mindsets for Health & Performance | Dr. Alia Crum

The episode opens by introducing Dr. Alia Crum, a tenured professor of psychology at Stanford and founder and director of the Stanford Mind and Body Lab, whose work examines how what people think and believe shapes the way their physiology reacts to food, stress, exercise and even medication. The introduction claims that beliefs about the nutritional content of food change how that food affects the brain and body "to a remarkable degree," and that the same holds for mindsets about exercise, stress and medication.

An early example comes from recent work in Crum's laboratory by graduate student Lauren Howe on children undergoing treatment for peanut allergies. As described, children who learned that side effects were a byproduct of a treatment that would help them, learned why those side effects arose, and heard that the side effects might even help them overcome the allergy moved through treatment faster and suffered less from those side effects. The introduction presents this as one example of how adopting particular mindsets might make people more adaptive and help them suffer less and perform better.

The introduction also notes Crum's background: besides being a research professor, she is a clinical psychologist and was once a Division I athlete and elite gymnast. Listeners are invited to keep a running question in mind, "What is my mindset about blank?", and apply it to stress, food, exercise and relationships while listening.

Mindsets get a working definition. They are described as:

core beliefs or assumptions that we have about a domain or category of things that orient us to a particular set of expectations, explanations, and goals

Stress is the first example. The key contrast is whether a person sees stress as enhancing and good for them or as debilitating and bad for them. These core beliefs are said to shape what people expect will happen when stressed, how they explain what unfolds, and what they are motivated to do. The same framing extends to intelligence, as Carol Dweck's work showed, and to food, medicine and other domains.

The discussion pushes back on how Dweck's work is often popularized. Her work is described as starting from implicit theories about whether intelligence or ability is fixed or can grow. Both views are acknowledged as oversimplified generalizations, since reality is "a bit of both." Still, humans need such simplifying systems to handle a complex reality, and the assumptions they settle on are "not inconsequential." Someone who believes intelligence is malleable is motivated to keep working after a setback. Someone who believes it is fixed may ask why they should work harder at math if they don't think they're good at it.

The lab's contribution is framed as widening both the range of mindsets studied and the range of effects measured, with a focus on health. The examples include these:

Stress: enhancing versus debilitating. Healthy food: disgusting and depriving versus indulgent and delicious. Exercise: whether one feels one is getting enough to gain the desired health benefits. Illness: cancer as an unmitigated catastrophe versus manageable or even an opportunity. Symptoms and side effects: a sign the treatment is harmful versus a sign it is working.

Two claims recur. First, at least in Western culture, people generally believe stress is debilitating and healthy foods are disgusting and depriving. Second, these mindsets have an impact "whether or not they're true or false," both through motivation and, as the lab's work has started to show, through physiological mechanisms that change what the body prioritizes and prepares to do.

The milkshake study is described as having been run at Yale, in the context of work with Kelly Brownell, who researched food and obesity, and Peter Salovey, who is credited with coining "emotional intelligence" and is now Yale's president. The research question is whether beliefs about what we eat change the body's physiological response to that food, "holding constant the objective nutrients of that thing."

Placebo research is offered as the reason the question is not outrageous. A sugar pill taken under the impression that it is real medication can produce physiological effects such as relieving asthma, lowering blood pressure or boosting the immune system. The discussion claims there is more evidence on placebo effects than on any other drug, because every new drug must outperform a placebo in clinical trials. It also flags a gap: there is little data comparing placebo to doing nothing, and that comparison matters for separating belief effects from natural changes in the body.

The study was conducted at the Yale Center for Clinical and Translational Research and used a within-subjects design. The same participants drank a milkshake at two time points a week apart. They were told the lab was designing shakes with very different nutrient concentrations for different metabolic needs of hospital patrons. One time, the shake was labeled a high-fat, high-calorie, indulgent shake of about 620 calories. The other time, it was labeled a low-fat, low-calorie, sensible diet shake. In reality it was the same shake both times: roughly 300 calories with moderate fats and sugars. The outcome was the gut peptide ghrelin, described as the "hunger hormone." Ghrelin rises signal a need to seek food. In theory, ghrelin falls in proportion to calories consumed, telling the brain to stop eating and revving metabolism to burn the nutrients just ingested.

When participants believed they were drinking the indulgent shake, their ghrelin levels dropped at a threefold rate stronger than when they believed it was the sensible shake. In short:

their bodies responded as if they had consumed more food, even though it was the exact same shake at both time points

Two points of significance are drawn. First, the study is described as, to the speaker's knowledge, one of the first to show a physiological rather than only a taste or satisfaction effect of believing one is eating something different. Second, the direction of the effect was counterintuitive. The expectation going in was that thinking you are eating healthily would be the better mindset. Instead, the "sensible" framing left participants physiologically hungry and not satiated, which "could potentially" correspond to slower metabolism. The stated conclusion carries a qualifier: for maintaining or losing weight, the mindset that one is eating indulgently and getting enough had a more adaptive effect on ghrelin "at least in that study."

From a neuroscience angle, the discussion points out that ghrelin regulation is not something a person can consciously decide. Yet a false statement about a shake's contents changed this subconscious, autonomic process. That suggests some crossover between conscious thought and autonomic pathways.