Hey Brainiacs,
Welcome to this week’s newsletter! Let’s explore how our mindset can affect different parts of our bodies and lives, and why the heck we still hiccup.
How far can our mindset really take us?
Alia Crum
Your mindset can affect your physical and mental health in a myriad of ways. Alia Crum has spent her career demonstrating just how potent your mindset is. She and her colleagues have shown that your mindset changes how effective exercise is1, how your body reacts to food2, and how stress affects your health3. This seems impossible, right? Well, let’s take a more common example. I’m sure almost all of us have heard of the placebo effect; someone is given a sugar pill and told it will help their pain, and their pain decreases even though it’s just sugar. Well, this is simply another example of our mindset – we expect pain relief and so we get it.
A study by Alia Crum and Ellen Langer has shown that the same thing can happen with exercise – if you think you’re exercising, your body responds like it’s exercising1. But if you don’t think you’re doing exercise, the effects are much more limited. Members of hotel cleaning staff were split into two groups: one was told about how many calories they burn doing standard cleaning activities (‘exercise mindset’) and the other was not (control). By the end of the study, the exercise mindset group had lost weight and body fat, and had lower blood pressure1, despite not having any changes in their job. Meanwhile the control group did not see any of these effects. So, is exercise just a placebo? I don’t think I would go that far. But I do think that your mindset about your lifestyle (‘my job requires a lot of exercise’ vs ‘I don’t exercise very much’) influences your lifestyle choices. That being said, I can’t think of another scenario in which you exercise and don’t know about it….
Your mindset about the food you eat also affects your body's response to the food2. Quick physiology lesson: when you haven’t eaten, your stomach produces a hormone called ghrelin to signal to your brain that you need food. Ghrelin levels rise until you get food, and then they should drop in proportion to how much you eat. But, if you’re anticipating the food, and think it will be tasty and satisfying, ghrelin levels drop more than if you think the food will be light and healthy2. Even when the food has the same number of calories2,4. Your mindset can literally change your body's reaction to the food you eat.
How did they do it? The same group of participants were given a milkshake advertised as indulgent and high calorie, and a week later, given a milkshake labeled as healthy and fat-free. However, both milkshakes contained the same ingredients and the same calories. Blood samples were collected from all participants before, during, and after eating the milkshake to monitor ghrelin levels.
Let’s get even crazier. Your mindset about stress can change how your body reacts to stress3. Generally, we are taught that stress is harmful, known as a ‘stress-is-debilitating’ mindset. However, there is another mindset we can adopt: the ‘stress-is-enhancing’ mindset. With this mindset, we believe that stress can push us to peak performance. And in a recent study, depending on the mindset employees were taught about, their body's responses to stress were completely different3. With a ‘stress-is-enhancing’ mindset, they responded to stress with a sharp increase in growth hormones, enhanced cognitive flexibility, and an attention to positive stimuli3. Plus, they said they felt positive. Meanwhile, a ‘stress-is-debilitating’ mindset led to a less prominent increase in growth hormones, a focus on negative stimuli, and negative feelings3. Their mindset about stress changed their stress response.
The claim is absolutely not that everything is your mindset. Your mindset will not cure you of cancer (although the ‘will to live’ argument is a hotly debated one!) or stop your diabetes. The point is that you can use your mindset to your advantage. How we view external stimuli affects how our bodies respond to them. Therefore, if we can put in the effort to rewire our brains and change our mindsets, we might feel real positive effects!
If you want to read more about it, pre-order my book Rewire!
Carol Dweck
But what about how we view ourselves? Does our mindset about ourselves – our personality, our intelligence, and our character- affect how successful we are? Let’s turn to Carol Dweck and the growth mindset5.
You’ve probably heard the terms growth mindset and fixed mindset, but let’s run through them. A growth mindset is where you believe that your intelligence, personality, and character are something you can develop6. You believe that you can cultivate these qualities through hard work and determination. Therefore, failure is painful but it doesn’t define you. Meanwhile, a fixed mindset is where you believe your intelligence, personality, and character are unchangeable6. This reduces your motivation to work hard, and causes failure to be personally devastating.
Why is this important? Well, people that are more successful tend to have a growth mindset, and our mindset affects our success early on7.
How do we know this? The effects of mindset on success has been shown in 7th graders (7). Students who believed their intelligence could be developed had an upward trajectory of grades, while students who believed their intelligence was fixed had a flat trajectory of grades. An intervention where students were taught about growth mindsets and the plasticity of intelligence led to an improvement in classroom motivation and reversed the downward trajectory of their grades (7).
Here we see that our mindsets can indeed change our abilities by changing our beliefs and views. The good news: if you think you have a fixed mindset, it’s not your fault. A lot of our mindset is due to our environment. The better news: you now have control over this! These studies show that we can change our mindset for the better.
Why do we get hiccups?
We all know that awful feeling of hiccups after eating too much. But have you noticed that you also tend to get hiccups when you’re stressed? Or excited? Well, the reason for this is likely due to the evolution of the hiccup. Researchers think that hiccups evolved from a need to switch between breathing in water and breathing on land, and that this reflex remained in fully land-residing mammals as a way to help babies!8. Interesting, right? Well, more interesting, the nerves that initiate the hiccup reflex used to go straight from brain to gills, but now go wandering much further, leading to more things triggering hiccups (like heightened emotions)9,10! Not sure evolution planned for that.
What are hiccups? How do we do that? Hiccups are a reflex (11), like kicking your foot when you’re tapped on the knee. Hiccups are triggered when your diaphragm contracts, and for some reason, the nerves connected to your diaphragm decide to signal the brain (8). These nerves include your vagus nerve and phrenic nerve. They send signals to your midbrain, which processes this information and sends signals back to the muscles in your diaphragm. This causes your glottis to close, expelling air from your lungs, and creating the classic ‘hic’ sound. Since the signal goes from your diaphragm to your brain and back to your diaphragm, this is known as a ‘reflex arc’ (11).
This reflex may have evolved from our fishy ancestors8. These ancestors are the guys who the vagus and phrenic nerves developed in, and we know that in these fishy ancestors, the phrenic nerve went straight from the brain to the gills. When they started making their way onto land, they probably used hiccups to switch between breathing systems8. But, now? Well, now we think that this reflex may be helpful for babies8. All baby mammals suckle milk, and hiccupping might be one way to remove the excess air they take in when suckling. Removing this air makes more room for milk, increasing caloric intake, creating a survival advantage. Plus, this reflex helps babies even before they’re born. Foetuses have been shown to hiccup12! When they hiccup, the brain region that controls the diaphragm becomes very active, and it is thought this may help babies learn to breathe before birth12. But…why do adults hiccup?
The vagus and phrenic nerves which trigger hiccups were initially very short and direct connections, but are now very long and wandering connections. Hence, a lot of things trigger hiccups, such as stress and excitement. The vagus nerve is known for regulating the stress response, and therefore, it is not surprising that stress can irritate this nerve. The good news is that the nerves can be tricked8. Drinking a whole glass of water keeps the phrenic nerve busy while you swallow, and having someone jump out at you initiates the calming response of your vagus nerve8. The nerves are thus distracted, and the reflex arc broken! Maybe now that you know these techniques should work, they will. It’s all about that mindset…
Life Updates
I finished recording my audiobook! Yay! I now have no voice.
Until next week,
Nicole x
P.S. Please leave comments with what topics you’d like to be covered in future weeks!
References
Loved this blog! Idea for future topic: amygdala hijacking. What do emotions do to our reasoning abilities? How/when to shut them down vs give them a seat, especially in interpersonal communication.