Recently, I was thinking about the differences between physical health and physical fitness, and wondering if there is an analogous distinction on the mental side. Googling, I found that the term "mental strength" is often used for the mental counterpart to physical fitness; "mental fitness" is tied too heavily to a narrower conception focused on intelligence and cognition.

I found this Verywell Mind article to be a good overview (and I recommend reading it though I don't assume it as a prerequisite). It identifies three broad components to mental strength: cognitive (thinking), emotional (feeling), and behavioral (acting).

I expect that most of the rest of what I write will be fairly obvious to many LessWrong readers, though I am not absolutely sure. I am still going to say them, for reasons Grognor articulated.

The post makes the most sense when read sequentially, but you can skim it or read whatever parts interest you based on the table of contents. The first section provides a few angles from which to think about mental strength. In the second section, I talk a little more about what I like about the "mental strength" concept and some of its implications. The third section talks about the relationship between mental strength and the LessWrong/rationality cluster.

Relation between mental strength and other concepts

Mental strength versus mental health

The Verywell Mind article includes a good comparison of the two concepts that I recommend reading. I will try to summarize it in my own words, with slightly different emphases.

Mental health is about your current mental state, or your average mental state over time. For instance, do you often feel stress and anxiety? Do you feel uncontrollable anger? Do you have depressive thought patterns? Or are you generally satisfied and content with yourself? Are you able to focus on the tasks that are important to you?

Mental strength is about the inner capacity and resilience you have developed (cognitively, emotionally, and behaviorally) to be mentally healthy across a range of life circumstances. Two people with the same mental strength might have different levels of mental health based on the circumstances they are in. However, on average, for people in similar circumstances, greater mental strength is likely to lead to greater mental health. (This is a bit of a simplification as neither mental health nor mental strength is one-dimensional, but it's still useful directionally).

The physical analogy may clarify this: physical exercise builds physical strength. If you take two people, one of whom has built more physical strength, and put them through the same physical ordeal, it's likely that the person with more physical strength will come out of the ordeal in better shape. But if you compare one person with physical strength who's going through a physical ordeal, and another weaker person who's relaxing, the former may be in worse shape!

To put it another way, mental health depends on mental strength and on how stressful the circumstances are. The more stressful the circumstances, the more mental strength is needed to achieve a given level of mental health. For instance, if you're living in a war zone with shooting happening all the time around you, the amount of mental strength you need to stay mentally healthy is probably higher than if you're living a relaxed life. In general, mortal danger, poverty, abuse, and high-stress work can worsen mental health and need more mental strength.

In a later section, I'll talk specifically of the mental strength demands placed in rationalist and effective altruist circles.

Mental strength versus mental toughness

Mental toughness seems to be a subset of mental strength focused on resilience and confidence. The concept was developed in the context of environments that place high expectations in terms of achievement, most notably sports.

Mental toughness seems like a important part of mental strength. But I don't think it covers the whole area; in particular, it seems focused on resilience and perseverance than on the wider gamut of cognitive, emotional, and behavioral skills. The development of the concept also seems heavily tied to sports and gaming where one copes with "losing" several times.

Mental strength versus intelligence

Mental strength has a cognitive component to it, and intelligence seems helpful with executing that cognitive component, that the Verywell Mind article describes as follows:

It involves the ability to think realistically. That means knowing how to recognize irrational thoughts and replace them with a more realistic inner dialogue. It’s also about speaking to yourself with kindness. So when you’re tempted to be overly critical of yourself, mental strength allows you to respond with self-compassion.

Having intelligence, however, does not seem sufficient to actually having the strength and skill to use that intelligence in the required ways. So while intelligence seems helpful it's not the same thing as even the cognitive component of mental strength.

Mental strength versus applied rationality

There seems to be a fair amount of overlap between applied rationality and mental strength. Specifically, the cognitive part of mental strength, and to some extent the emotional and behavioral parts, seem to overlap closely with the self-directed portions of applied rationality. Applied rationality can also include several tactical aspects that aren't tied to mental strength (e.g. insights on how to manage one's finances).

I think of the applied rationality approach to developing mental strength as one school of thought on how to develop mental strength. Meditation practice, particularly mindfulness meditation, might be another school of thought (and there may be overlapping ideas between them).

What I like about the mental strength formulation

What I don't like about mental health

Some kinds of actions are risky for one's mental health, just as some kinds of actions are risky for one's physical health. This risk is important to bear in mind, but at the same time there could be other benefits to doing it. For instance, maybe volunteering to provide medical services in a war zone is bad for one's physical and mental health, but the benefits it creates for the world make it worthwhile.

When we're stuck with "mental health" we're stuck on a trade-off curve between mental health and whatever else we are trying to optimize for. At least intellectually, this means that if we acknowledge and give importance to mental health, this pushes us away from taking risks. And to the extent that people who take on more risks and stresses suffer worse mental health, it just gets seen as them being less (mentally) healthy. And if we always want to "fix" our mental health issues, this pushes us to exiting challenging situations.

The "mental strength" concept helps provide the hidden term that connects mental health with the challenges one undertakes. And increasing one's mental strength means pushing out one's tradeoff curve. We can thus recognize more that people who take on more stress and have worse mental health may not be less mentally strong than others. And we can also think about ways that we can raise our mental strength to the levels needed for the challenges we want to take on.

Moving from "mental health" to "mental strength" is moving from a reactive to a proactive approach to helping one's mind thrive.

PS: It seems absolutely ok for somebody to decide that their path to mental health shall be to stay away from challenges rather than to build mental strength. And definitely there will be cases where quitting a challenging situation is the right move to preserve and restore one's mental health. I also think that working with the mental strength formulation allows us to explore the tradeoff more intelligently.

The (partial) buildability of mental strength

Hopefully, mental strength can be built! As it's multi-dimensional, the dimensions that are important will depend on the kinds of challenges one wants to take on.

For instance, if you want to excel in competitive sports or gaming, mental toughness, that allows you to engage in repeated practice and experience repeated failure, seems important.

With physical strength, we have several regimens of exercise that people undertake explicitly with the goal of building that strength. The general pattern is very standard: expose the body to stresses in a controlled environment (e.g., by making it lift weights, or run long distances). Then give the body time to recover. What doesn't kill it makes it stronger. Hormesis.

Natural exposure versus deliberate exercise

For many people, "natural" levels of exercise, such as walking around for their day-to-day activities, constitutes enough exercise to maintain the level of physical fitness they consider important. However, people serious about building physical fitness do not rely on natural exercise -- they engage in deliberate exercise that stresses the body to unusual levels, and then rest to recover from it. For instance, people who train for physical sports do exercise over and above direct practice of the sport, in order to improve their physical fitness.

I expect something similar to be true in terms of the best methods to develop mental strength: for many people, "natural" levels of cognitive, emotional, and behavioral stimulation that day-to-day activities provide will be enough. But those seeking to achieve extraordinary feats of mental strength will likely benefit from some form of deliberate exercise.

However, there is a difference between the physical and mental realms that calls the above into question. Namely, in the physical realm, thanks to tremendous technological progress, many of us lead sedentary lifestyles where "natural" levels of exercise are low. In the mental realm, the opposite may be true: the average person may be experiencing a pretty thorough mental workout just from day-to-day life. So I still expect that some people will need deliberate mental exercise, but the proportion of people who need mental exercise to build mental strength may be much lower than the proportion of people who need physical exercise to become physically fit.

But the opposite argument could also be made: mental strength is much more instrumentally useful in modern life than physical fitness, so there is more of a case for deliberate exercises to build mental strength.

I so happen to think that for the kinds of mental strength I am most interested in developing, the "natural" work I do is best for developing that mental strength. However, I think I might change my mind, and/or move to other activities where building mental strength ahead of time is important. I think awareness of the concept of mental strength has made me open to this possibility.

Deliberate exercises to build mental strength (as opposed to addressing mental health)

While there are a number of exercises designed to build cognitive skills, there seem to be relatively few that are designed to build mental strength in a broad way. The biggest cluster I can think of is meditation, and in particular, mindfulness meditation.

Most therapeutic approaches such as cognitive-behavioral therapy (CBT) seem focused on addressing mental health issues -- solving cognitive, emotional, and behavioral challenges one has. While the application of these has some side-effects in terms of improving mental strength, my sense is that they are not primarily strength-building tools.

Mindfulness meditation techniques, on the other hand, seem more like the mental equivalent of weight-lifting -- you train your mind to focus on only one relatively small thing (e.g. your breathing) and to observe its own thought patterns.

With this thinking and understanding, it makes a lot of sense why a lot of people in high-stress positions (such as CEOs) practice meditation, even if they didn't have any noticeable mental health issues and even though the opportunity cost of their time may be huge. It's because: (a) they need more mental strength to cope with the demands of their high-stress position, so (b) they benefit a lot from general-purpose exercises to build such mental strength, and (c) meditation is a widely developed cluster of such techniques, with several benefits such as that it can be practiced alone over a wide range of places and times. From this perspective, that CEO meditating for 15 minutes in the evening is just like that football player lifting weights at the gym.

I wonder if there are large not-yet-popularized sets of mental strength-building exercises that people are missing out on because they aren't thinking explicitly in the terms I laid out. I say "not-yet-popularized" because I'm confident such exercises exist but they may be limited to specific realms that have extreme requirements (such as some kinds of military training) and are not part of the broader culture.

Switching for a moment to the physical analogy, imagine that people didn't have the concept that competitive sports players need to do physical exercise beyond just doing practice of the sport. If let's say a soccer player wasn't a fast runner, the solution in that world would just be to practice more soccer and pay attention to one's speed. But with running available as a separate exercise, it's possible to train much more intensively on that front. (I recall reading somewhere that a few decads ago, deliberate exercise not directly tied to the sport was much less common for sportspeople, but over time the benefits of such deliberate exercise for improving physical fitness were more broadly appreciated. Unfortunately I am having trouble finding the reference, so take this with a pinch of salt).

Going back to the mental strength side, what if your problem is that when you receive criticism, you find it hard to take? Without a concept of deliberate exercise, the solution would be to just use as practice whatever occasions life serves up to you of criticism. But with a concept of deliberate exercise, you may choose to engage in activities where you'll get a lot of criticism (e.g., write an online comment on a news site), or even to artificially receive a lot of criticism at random (e.g., pay somebody to unpredictably start shouting at you several times a day while you are engaging in an activity jointly).

Mental strength and the rationality community

Saving the world takes mental strength, and a lot of rationalist writing has the building of such mental strength as a goal

The sequences were started by Eliezer Yudkowsky partly to close some of the inferential distance that others needed to bridge in order to understand the importance of AI safety. They were also designed to provide people with the tools to think about and tackle some of the biggest challenges facing us. One angle to these challenges is the mental strength needed.

If you want to save the world, you need a lot of mental strength. Even contemplating it requires mental strength. Being willing to face some of the challenges facing humanity, due to which the world needs saving, requires mental strength.

I think Nate Soares' Minding Our Way is largely about building mental strength.

One way I think of the rationalist flavor of building mental strength is that it starts with the cognitive, and then builds on that to tap into the emotional (feeling) and behavioral (acting) parts. In contrast, it seems to me that meditation starts with the behavioral (acting) parts, and then uses those to delve into the cognitive and emotional parts.

The greater challenges of the rationalist, longtermist and effective altruist communities is at least part of the reason for mental health challenges, and highlights the need for greater focus on building mental strength

There are a few closely tied (and mutually reinforcing) ways that communities of people who intersect heavily with the LessWrong readership may need more mental strength:

The intellectually and emotionally exhausting nature of the search for truth, that often involves updating one's previously held beliefs one may be attached too
Sincere, rational belief that there are a lot of problems and risks in the world, possibly including existential risks; examples:
- Belief in a nontrivial probability of AI foom and doom
- Belief in a nontrivial probability that there's a large amount of morally relevant suffering humans ignore, such as the suffering of farmed and wild animals, or the potential suffering of future sentient beings
Resultant desire to act in seemingly weird and difficult ways to improve or protect the world (which ties back to 1; if you are actually trying then you want to have access to the truth)
Lack of social support and respect for some of these beliefs and for the resultant worldviews, and therefore potential social isolation

Others on LessWrong and elsewhere have talked about various angles of these in more depth. My rough sense (which could be off) is that at least some of the mental health challenges faced by people in the rationality community and related communities are tied to these factors. A lot of these are intrinsic to what it means to be a rationalist, longtermist, or effective altruist, so we wouldn't want to fundamentally change the underlying patterns. The best solution to the likely mental health impacts, therefore, seems to be to build mental strength. This could be through some combination of natural exposure and deliberate exercise.