Last week, I talked about my process [1] for doing intensive research combined with building new habits that I’ve been using this past year in my Foundations [2] project.
One question that sometimes comes up when I emphasize the value of doing research is whether reading a lot of books is necessary. Did you really need to read books to tell you that exercising was important? Or that you shouldn’t eat junk food? That you should get to bed on time?
I think this “I know that already” problem infects a lot of areas of self-improvement. In brief:
- Hindsight bias is strong. Everything is obvious [3] once you know the answer. The value of research is usually in telling you which of two plausible theories is true, or which advice from different, seemingly sensible approaches works best.
- Reading is attentional, not just informational. My heavy [4] reading [5] lists [6] didn’t [7] just [8] teach [9] me [10] new [11] things [12] about [13] each [14] topic, they also forced me to think about those themes for the entire month. Since much of improvement is simply focusing on something long enough to make a change, this shift in focus is much easier to sustain if you do a lot of reading.
However, even if I think we rarely overhaul our entire belief system upon deeper research of a topic,1 [15] I wanted to talk about some areas where I changed my mind during the last twelve months of research.
For each foundation, I’ve picked the belief that I changed my mind about that made the biggest difference in my actual behavior.
1. Fitness: Cardio matters more than lifting weights for health.
As I mentioned in my fitness day one update [16], for years I had largely done strength training. Some of this was the classical vanity of a skinny twenty-something kid wanting to bulk up. But part of it was also that, at the time, I enjoyed lifting weights more than running or cycling.
Coincident with that preference was the belief that exercise was exercise. You should exercise to be healthy, but otherwise the choice was up to you.
Now I largely believe that while both strength training and cardiovascular exercise have benefits for health, the benefits are largely distinct [17]. Strength training helps build bone and muscle mass, something that is especially important as you age. But cardiovascular exercise has the stronger relationship [18] with health and reduced mortality outcomes.
2. Productivity: Happiness, not stress, leads to productivity.
We’re taught a confusing mix of messages about work and productivity. We need to hustle, but also to have balance. We need to lean in, but also practice self-care. Results come from straining ourselves in deliberate practice [19], but also from flow [20].
I now think a lot of strain is overrated. The research shows [21] that people are most productive at work when they have more positive emotions. And that positive inner work-life comes largely from feeling like they are making progress.
In other words, forget the masochistic talk about grinding and hustling. Focus instead on the steady drip-drip-drip of making incremental progress towards your big tasks.
3. Money: Bonds are riskier than stocks in the long-term.
Most investors shouldn’t be picking individual stocks. I’d even go further and say that most investors shouldn’t even be putting their money with experienced advisors who pick stocks. Buying a low-cost index fund [22] is the right choice for most people.
But even though I’ve long been persuaded of the efficacy of index investing, which was amply confirmed doing the research that month, one area I changed my mind with had to do with asset allocation.
Traditionally there’s an understanding that you should hold a mixed portfolio of stocks and bonds [23]. Stocks tend to be riskier, but also higher return. So, for younger investors with more time until retirement, a high-stock portfolio is best. But this should slowly add in more bonds, as this leads to greater security (at the price of lower returns).
Interestingly, I’ve now become largely convinced that, in the long-run, stocks don’t just perform better, they’re actually less risky than bonds [24]. Bonds have some undesirable features so that, even if their volatility is lower, the actual risk of holding them goes up over longer time horizons. Practically speaking, this didn’t change my actual portfolio. But it does suggest that the reason to hold a mixed portfolio should depend much more on your time horizon rather than your risk tolerance.
4. Food: Saturated fat is still bad for you.
Until this project, I had mostly a passing interest in nutrition. From that, I had basically imbibed a pretty common message about the changes in research-grounded advice that goes something like this:2 [25]
- Way back in the dark ages, scientists thought saturated fat was bad for you.
- Because of this, we made everyone switch from butter to margarine.
- Except later we learned all this margarine has trans fats, which are even worse!
- In addition, new research says that maybe saturated fat isn’t actually bad for you!
- Scientism at its finest, the nutrition advice we were all following for years actually made us fatter and unhealthy.
But after doing the research for this month, I’ve realized this is basically false. Saturated fats are still bad for you [26], and the evidence base in favor of lowering saturated fat is one of the strongest in all of nutritional research, including not just epidemiological work, but controlled feeding trials, mechanistic work and more.
It is true that public health was behind the ball on trans fats. But this issue is basically moot because they’re not really in the food supply anymore.
It is true that public health messaging has changed. The low-fat advice was deemed overly simplistic [27], dietary cholesterol doesn’t have much impact on blood cholesterol (so egg yolks are largely fine) and added sugars and refined carbs are being elevated in their concern for contributing to the obesity epidemic.
But it is simply not the case that there’s been a reversal in scientific evidence on whether saturated fats are unhealthy. Butter isn’t a health food, sorry.
5. Reading: Paper beats ebooks.
Prior to the reading this month, I had largely believed that the medium didn’t matter so much when it comes to your ability to retain what you read: paper, ebook or audio recording were all about equally good, provided you paid attention to them.
However, I now think the balance of evidence does favor paper [28] as a medium, even if it’s slight. As a practical matter, I don’t think this makes a huge difference—I’m rarely listening to an audiobook under the same circumstances when I would be reading, and practical considerations often encourage me to go for Kindle rather than paper. But, I do think if a book is difficult and important for you to study, you’re probably best off with a hardcopy.
6. Outreach: Friends help you live longer.
The health benefits [29] of social connectedness are in the same ballpark as those associated with other well-known lifestyle improvements to health such as diet, sleep and exercise.
This finding surprised me. I guess I always felt like socializing was something ephemeral—how could it possibly impact your body?
But the proposed mechanism [30] makes sense to me: social isolation causes chronic stress. Chronic stress raises blood pressure and suppresses the immune system, leading to greater infection and mortality.
7. Sleep: Trying hard to sleep perfectly is counterproductive.
Like many people, I was originally impressed a few years back by Matthew Walker’s Why We Sleep. At least until it was pointed out how sloppy [31] Walker was with his reporting on the science.
Walker’s book had convinced me that not only was getting eight hours of sleep nightly a health imperative, but that we should probably take our sleeping as seriously as our exercise.
However, the full research I did that month painted a different picture. While getting enough sleep is important, actual sleep needs vary quite a bit, so it’s probably not the case that everyone needs exactly eight hours [32]. Moreover, sleep differs from exercise in being a state that can only come about involuntarily—you can’t make yourself sleep, and putting too much pressure on sleeping well actually makes you sleep worse [33].
8. Reflection: A (little) delusion can be a good thing.
One of my longstanding assumptions has been that it is better for us to know the truth than believe a lie. Is does not imply ought [34], and so it is better that we have the best possible picture of the territory ahead of us, so that we can make better decisions.
I still (mostly) hold to this view, if only because I find the idea of wild self-delusion inherently unpalatable. But doing the research this month convinced me that, ironically, the case that some (mild) self-delusion may be adaptive is probably stronger than the norm of ideal rationality. Self-efficacy [35] and mild forms of positive self-regard can become weakly self-fulfilling prophecies, and it is not obvious that the benefits of these are achieved at a fixed point.3 [36]
9. Connection: Being married (but not having kids) is associated with greater happiness.
As a parent, I had always been somewhat disappointed by the finding that people’s life satisfaction typically drops [37] after they have kids. It’s not totally baffling—after all, taking care of a human being is a lot of work, and having children can increase economic and relationship pressures. But it would have been nice if the obvious love we have for our children would figure into the calculation as measured by psychometricians.
On the flipside, I was positively surprised to find out that the relationship between marriage and happiness is not only positive [38], but the magnitude is very large and robust to many possible confounds.
I still suspect this is correlation rather than causation, but it’s still a nice antidote to the stale jokes about “the old ball-and-chain.”
10. Focus: ADHD is best treated through medicine.
Until this project, I admit, I didn’t know much about ADHD. I had largely bought into the idea, commonly portrayed in the media, that we’re overprescribing drugs to kids, just because they can’t sit through boring classes and would prefer to have recess.
My textbook [39] for this month by Russell Barkeley, one of the foremost experts on the disorder, painted a very different picture. In genuine cases, ADHD is mostly heritable, and behavioral interventions (such as those that work well with depression, anxiety, OCD and other mental health issues) don’t work particularly well. In contrast, pharmaceutical treatment works remarkably well, and squeamishness about prescribing them is robbing many kids of a normal childhood.
(Interestingly, the other contributors to the volume, while supporting Barkeley’s messaging on treating kids, echoed some more common concerns of overdiagnosis in adults. One of the contributors raised an eyebrow to the idea that many otherwise high-functioning adults have proper ADHD, arguing that impairment is the sine qua non of the disorder, so being particularly high-functioning was largely disqualifying.)
11. Organization: Decluttering is better done all-at-once rather than bit-by-bit.
This was one of my worst foundations going into the project, so it’s no surprise that some bad beliefs had held me back. In particular, I believed prior to the project that it was probably best to make decluttering a regular habit—something you do in little chunks here and there. Marie Kondo’s book [40], however, convinced me that this approach tends to be self-defeating.
The real difficulty with being tidy is having too much stuff. We have too much stuff because we have a hard time making a decision about what to throw out. This decision is hard to make about each possession in isolation, but benefits from seeing whole categories at once. In other words, that tattered sweater may seem reasonable to hang onto until you actually inventory all your clothes.
Decluttering this way is more work. But it works better.
12. Service: Empathy is overrated.
I went into this month thinking empathy was the cornerstone of our moral sense. Psychologist Paul Bloom’s book argues that empathy is not only unnecessary for moral sentiments, but actually counterproductive [41]. I left reading his book largely agreeing with his point of view.
To understand, it helps to be precise about what empathy is: putting yourself in another person’s position and feeling, vicariously, what they feel. So empathy means recoiling your foot when you see another stub his toe, or imagining what it would be like to be sick, starving or alone.
Bloom contrasts this with cognitive empathy, which involves understanding a person’s emotional state without necessarily sharing it, and compassion, which is a more diffuse desire to help people without necessarily sharing in their miseries.
Bloom makes a long list of this narrower version of empathy’s flaws: it is innumerate (so we feel it equally for one person and one million people), it is biased (we feel more sympathetic to those like us than unlike us), it can encourage us to look away (does hearing about far-away suffering bum you out? It’s easier to ignore it than make a donation), and it can even encourage tribalism and violence by causing us to sympathize selectively with victims.
In contrast, Bloom argues that our moral sentiments are better founded on reason and compassion. Reason, because it can help us make the correct decision in complex situations. Compassion, because it allows us to help others without the need for burnout or bias.
Footnotes
- One more reason to read the right books in the first place. Changing beliefs is hard, even when you’re wrong.
- For instance, Michael Pollan makes essentially this argument in In Defense of Food [42].
- Mathematical aside, a fixed point [43] is a place where the output of a function is the same as an input. Self-fulfilling prophecies are recursive beliefs where the output (what you believe) determines the input (what’s actually true). Most beliefs, of course, are not self-referential in this way, but some beliefs such as “I’m going to have a great day today” are probably (weakly) self-referential, in that the belief itself can create some of the behaviors and attitudes that make its prediction accurate. For strict rationality to be optimal, you’d need to assume that the ideal outcome is at a fixed point (where you believe exactly what is true). But this may not be the case. It may be the case that believing you’re going to have an amazing day only leads to having a pretty good day, but that this is still better than the fixed point of “My day is going to be alright.”