= 27d567bc2d48d9f40e9ccc20ea370b15)
The Science of Cutting Peppers
Summary: Rigorous scientific experiments are hard to apply in daily life but we still want to try out and evaluate things like self-improvement methods. In doing so we can look for things such as a) effect sizes that are so large that they don't seem likely to be attributable to bias, b) a deep understanding of the mechanism of a technique, c) simple non-rigorous tests.
Hello there! This is my first attempt at a top-level post and I'll start it off with a little story.
Five years ago, in a kitchen in London...
My wife: We're going to have my friends over for dinner and we're making that pasta sauce everyone likes. I'm going to need you to cut some red peppers.
Me: Can do! *chop chop chop*
My wife: Hey, Mr. Engineer, you've got seeds all over! What are you doing to that pepper?
Me: Well, admittedly this time I was a bit clumsy and there's more seed spillage than usual - but it's precisely to avoid spilling seeds that I start by surgically removing the core and then...
My wife: Stop, just stop. That's got to be the worst possible way to do this. See, this is how you cut a pepper, *chop chop chop*. Nice slices, no mess.
Now, ever since then I've cut peppers using the method my wife showed me. It's a much better way to do it. But wait! How do I know that? Don't I realize that humans are subject to massive cognitive biases? Maybe I just want to please my wife by doing things her way so I've convinced myself her method is better. Maybe I'm remembering the hits and forgetting the misses - maybe I've forgotten all the times my method worked out great and the times her method failed. Maybe I am indeed making less of a mess than I used to but it's simply due to my knife skills improving - and that would have happened even if I'd stuck with the old method. And there are probably a dozen more biases and confounding factors that could come into play but I haven't even thought of.
Don't I need to do a test? How about cutting up lots of peppers using the two alternative methods and measuring seed spillage? But, no, that's not good enough - I could subconsciously affect the result by applying less skill when using one method. I'd need a neutral party to operate the methods, preferably a number of people. And I'd need a neutral observer too. The person who measures the seed spillage from each operation should not know which method was used. Yeah, a double blind test, that's the ticket. That's what I should do, right?
No, obviously that's not what I should do. There are two reasons:
A) The resources needed to conduct the suggested test are completely disproportional to any benefit such a test might yield.
B) I already bloody well know that my wife's method is better.
The first reason is obvious enough but the second reason needs a bit more exploration. Why do I know this? I think there are two reasons.
* The effect size is large and sustained. Previously, I used to make a mess just about every time. After I switched methods I get a clean cut just about every time.
* I understand the mechanism explaining the effect very well. I can see what's wrong with the method I was using previously (if I try to pull the core through a hole that's too small for its widest part then some seeds will rub off) and I can see how my wife's method doesn't have that problem (no pulling the core through a hole, just cut around it).
I'd like to try to generalize from this example. Many people on this site are interested in methods for self-improvement, e.g. methods for fighting akrasia or developing social skills. Very often, those methods have not been tested scientifically and we do not ourselves have the resources to conduct such tests. Even in cases where there have been scientific experiments we cannot be confident in applying the results to ourselves. Even if a psychology experiment shows that a certain way of doing things has a statistically significant1 effect on some group that is no guarantee that it will have an effect on a particular individual. So, it is no surprise that discussion of self-improvement methods is frequently met with skepticism around here. And that's largely healthy.
But how can we tell whether a self-improvement method is worth trying out? And if we do try it, how can we tell if it's working for us? One thing we can do, like in the pepper example, is to look for large effects and plausible mechanisms. Biases and other confounding factors make it hard for us to tell the difference between a small negative effect, no effect and a small positive effect. But we still have a decent chance of correctly telling the difference between no effect and a large effect.
Another thing we can do is to use some science. Just because a rigorous double blind test with a hundred participants isn't practical doesn't mean we can't do any tests at all. A person trying out a new diet will weigh themselves every day. And if you're testing out a self-improvement technique then you can try to find some metric that will give you an idea of you how well you are doing. Trying out a method for getting more work done on your dissertation? Maybe you should measure your daily word count, it's not perfect but it's something. As xkcd's Zombie Feynman would have it, "Ideas are tested by experiment, that is the core of science."
Erring on the side of too much credulity is bad and erring on the side of too much skepticism is also bad. Both prevent us from becoming stronger.
1) As good Bayesians we, of course, find psychologists' obsession with null hypotheses and statistical significance to be misguided and counterproductive. But that's a story for another time.
= 783df68a0f980790206b9ea87794c5b6)
Loading…= b715d02e85f7b3b4ae65ca3d3e450868)
Subscribe to RSS Feed
= f037147d6e6c911a85753b9abdedda8d){kind=logo}
Comments (68)
I especially agree with
When we're seriously in doubt, understanding mechanism can produce hypotheses to test. It's how we prune our search space.
In this case, we have two methods, (thanks for explaining what they were, by the way), both with plausible mechanisms to decrease mess. After even brief experimentation, it is obvious that method 1 has a specific flaw that prevents it from working well, and that method 2 works better because it suffers from no flaw as significant.
This last point is what is sometimes missed in (less careful application of) evo psych; plausible mechanisms are not necessarily well-understood mechanisms and probably can't be until they have been seen in action.
See also Seth Roberts, who's done a lot with self-experimentation by way of many small low-cost experiments looking for large effects.
Seconded.
Reading through his blog shocked me at just how much important stuff you can learn by simple tests.
I've personally experienced several benefits from the results of his/my self experiments. The most noteworthy to this community would be that I have eliminated 3 different causes of mental fatigue. For instance, due to changes in diet, I can go without food all day and still be mentally productive, whereas before, if I hadn't eaten in a few hours, I wouldn't be able to think clearly enough to be productive.
Details? Please? ;-)
In short, replace carbohydrates with animal fats.
I still get hungry if I don't eat all day, and it can still have some negative impact, but it's an order of magnitude less of a problem.
It took a little while for my body to adapt to the changes. I didn't actually take notes, and it was sort of a gradual transition for me, so I'm not sure how long everything took. I'd expect a lot of the benefits to come after the first meal, but by a month or so I think most things stabilized and my tastes adjusted to fit my diet better.
If anyone wants to know more details, I'm more than happy to share, but I'm not sure exactly which parts would be interesting. Just PM me and we can chat.
Why animal fats in particular? This is somewhat disheartening as I find both the idea and the taste of eating mammals to be physically nauseating. Poultry and fish aren't as significant for me, but I don't eat much of those either.
Since you've significantly increased your animal fat intake, how has your animal protein intake changed? Do you just add lard to your diet, or do you eat really fatty cuts of meat?
Partly for the saturated fat, partly for less extreme amounts of omega-6 (though some plant oils are not as bad as others), and partly the personal fact that my stomach doesn't seem to like significant quantities of olive oil, but craves large amounts of animal fat. Whipping cream and butter are both mammal fat that don't require killing the animal - eggs fried in butter are quite tasty :)
I never really monitored the amount of protein I eat, but it has to have gone up. I do eat fatty cuts of meat, but I add a lot of nearly pure fat to my diet, so it's a bit of both.
Good point.
I like butter, though not as much as olive oil, but I also eat a good deal of cheese and eggs, so I guess I already eat a fair quantity of animal fat, just not animal body fat.
Good Calories, Bad Calories is a comprehensive and detailed discussion of why the conventional wisdom on diet is flawed. Here's a less rigorous run down of the different fats. Saturated fat is the main reason to prefer animal fats as it is hard to find in non animal sources. One non animal derived option is coconut oil.
Most people who question conventional wisdom are cranks. As a non-expert, I am not capable of evaluating the object-level arguments on the subject. Why should I grant Gary Taubes any more credibility than any other random person who writes a book with lots of footnotes?
I haven't read the book either.
I don't know about heart disease and cancer risk and I'm in roughly the same epistemic position as you on that.
For plain old fat loss, though, there's more reason to believe that more fat and protein compared to carbohydrates is effective. First, that's what athletes and their nutrition coaches do -- it's always useful to look at the practices of people whose livelihood depends on objective success. Second, I've read a fair number of CDC studies showing that diets have modest to zero effect -- and usually the test diets do not have a high protein + fat to carb ratio. That's weak evidence, but evidence: the stuff that doesn't work is not the candidate in question. Third, it just makes sense that simple sugars break down into glucose faster than anything else, which means a quick spike in blood sugar instead of slow release over time, which means you'll be hungry soon after. No, plausible mechanisms aren't science, but they help. Fourth, it's easy enough to perform the experiment yourself for three months and see what happens.
If you are not confident in your own ability to recognize cranks (either in general or in a particular field) then sticking with conventional wisdom may be your best option. In general my experience is that it is not very difficult to spot genuine cranks however but YMMV. I'd suggest that health in general is a poor place to put great faith in conventional wisdom however since there are many powerful interest groups influencing things like government issued recommendations whose interests are not always well aligned with yours.
Nutrition and diet are relatively amenable to self experimentation however and so at least some claims are fairly easily testable. Obviously you aren't going to be able to confirm claims of reducing your risk of heart disease or various cancers (for example) in the short term but claims about weight loss are trivial to verify and it is not terribly difficult to test other claims by having blood work done (triglyceride levels, LDL/HDL ratios etc.) and by keeping a record of possibly diet related symptoms under different regimes (mood, energy level crashes, digestive problems, etc.).
Thanks for the information. Although I haven't read it, I'm familiar with the topics covered by Good Calories, Bad Calories, and feel that the points it brings up have good support among people who care about the scientific method.
The two pages on Mark Sisson's website that you linked to only claimed that saturated fat isn't bad; I can agree with that, but what I'm really interested in is why you seem to feel that they are especially healthful. It doesn't seem like he claims that.
Well he tends to emphasize that the key to healthy eating is to minimize refined carbohydrate intake and he recommends a protein intake in the range of 0.7-1.0g per lb of lean body mass so fat intake is in part driven by the need to make up the rest of your target calorie intake. Saturated fat seems to be the a fairly healthy way to make up the calorie deficit given the options.
That a much less dramatic claim than it sounded like you were making at first, which is good for me, since it doesn't make me feel obliged to add animal fat to my diet.
I do eat a lot of fat, though mostly unsaturated (nuts and avocado). I also eat a lot of carbs, but I try to eat almost no refined carbohydrates; your example of beans and rice amuses me because brown rice and beans are a significant portion of my diet.
I think beans and rice was actually jimmy's example but yeah, rice is pretty horrendous health wise, brown or not. The jury's still out on beans from what I've read. You can't easily match the calorie intake from grains without upping your fat intake though since you need to eat a hell of a lot of green vegetables to match the caloric value of grains.
Done that myself. It fixes a lot of problems: more energy, easier to stay full for longer on less food, the only "diet" I've ever tried that worked.
It's strange that something so "unnatural" seems to be good for the body along a variety of dimensions. (It's unnatural in the sense that animal products are expensive, and require a lot of biomass input, and so it's weird to make them a dietary staple whereas most of the world lives on grains.)
It's natural in the sense that it seems to be closer to the pre-agricultural diet of hunter gatherers which represents a much larger period of time in our evolutionary history than the relatively recent rise of agriculture. That's the idea underlying the Paleolithic Diet which I've had a lot of success with.
Interesting. I've had little luck with that in the past, due to carb cravings. A few days ago, though, I googled "craving raisins and cheese" (my usual craving) and found a page that suggested this (and other sweets-cravings) were likely a need for tryptophan.
So, yesterday and today I've been taking some L-tryptophan and it seems to have knocked my carb cravings down a bunch; I've not had a compelling urge to eat anything sweet today as yet.
I used to desire carbs, but not particularly more than fats. My appetite for carbs has almost disappeared though. When I look at a plate of rice and beans, my body gives me the "that's not food. I don't want it" feeling.
Thanks for the L-tryptophan tip. I might get some and test it on some carb loving friends.
Mmmm... rice and beans...
Just to add to the anecdotal data, I've had the same experience upping animal fat and being able to be productive (mentally and physically) even without eating, and I work a physically demanding job at night, either of which alone can induce fatigue. I eat mostly butter, egg yolks, cream, coconut oil, and fatty cuts of meat like pork belly and fatty ground beef (epsom salts, mineral water and magnesium supplements take care of any muscle soreness).
The thing holding me back from much more self-experimentation is a good data capture tool. Anyone have any recommendations (web, mac, iPhone)?
I'd like to know a) when we say "spilling seeds" what exactly do we mean? Spilling them into the pepper-pieces, or just spilling them over the table in general? With that in mind, what are the differences between the two methods? Your (old) way sounds possibly like my way, which I always thought was pretty good. But that might just be me being biased in favor of my own ingenuity.
I always start by cutting off the top of the pepper (high enough that it leaves a hole in the top-piece, because the little dip in the top goes lower than the place I cut at). This a) let's you pull out the core, probably in the "surgical" method you were referring to. But it does leave those little rubbery things that you need to deal with on the inside which sometimes have seeds left.
My old method was to cut a circle into the core end around the core and then pull out the core - typically leaving lots of seeds inside the pepper. Those seeds would get more widely distributed as I proceeded to cut up the rest of the pepper.
The method my wife taught me is to start cutting on the other end and make multiple parallel cross sections until I get to the core. The pepper now resembles a cup with a core in the middle. At that point I alter the direction of slicing and cut off the sides of the cup, leaving only the core. The advantages of this method are that a) I can clearly see the core when I am cutting around it, so I don't accidentally cut into it and b) I don't have to pull the core through a hole that tends to be too small for it.
I'm sure there are multiple non-stupid ways to slice a pepper. I'm quite bad at what we could call 3D reality manipulation and have to be explicitly taught obvious things. My father (also an engineer) is the same way.
I've had good luck with cutting off both the top and bottom 0.5cm of the pepper, which leaves me with a capless pepper cylinder containing the core. I can then slice out the core. Then before doing anything else with the pepper, I run water through the now-empty cylinder to rinse out any clinging seeds.
My favorite method is to cut it in half vertically/meridianally without cutting the core nor the stem portion, crack the two sides away from the core and discard it, then flatten and slice up the sides. With care, the core is undisturbed and intact, and you can slice up the rest quickly--maybe 15-20 sec per pepper to julienned, another 15 to diced.
However, if you are looking for pretty rings, which I think are often far too large to be bite size, my* method doesn't produce them.
(* 'my method' meaning as a friend/chef taught me, and is partially illustrated in Rombauer's "Joy of Cooking")
Following the theme of the post, perhaps the lesson is for one to look for sources outside oneself for criticism and alternatives so you can identify opportunities and metrics for improvement
My preferred method.