Hindsight Devalues Science

Ouch. I had vague feelings that something was amiss, but I believed you when you said they were all correct. I knew that sociology had a lot of nonsense in it, but to proclaim the exact opposite of what actually happened and sound plausible is crazy (and dangerous!).

These examples emphasize the benefit of frequently taking calibration tests, where we assign probabilities to answers and then checks those answer for calibration errors. Perhaps someone could create a website where we could do this regularly? Just collect a large list of questions like the ones above, questions with true answers but where we have intuitions about what the answer might be, and then have us answer those questions with probabilities, and then show us a calibration chart for the last X questions. Yes, collecting the good questions will be most of the work.

As a lack of known causes fear, hindsight bias delivers us the comfort we desire at all times, the easy model that we build, rather than the unexpected unknown that causes anxiety. In that way we learn -- some might prefer this unenlightened state, as hindsight bias smoothes their mental ships away from the scholes of uncertainty and self-doubt.

Eliezer, I don't have any contribution to make to the conversation. I just want to tell you that the last 10 or so posts from you have absolutely blown me out of my socks. Without a doubt, some of the most impactful and insightful stuff I've read in my 10+ years on the web.

Please keep it up.

And yes, I realize there's an irony to professing what is really a byline bias on this site. :-)

Frankly none of the five examples strikes me as something I could have predicted, nor ever struck me as such. Nevertheless, social science may indeed produce few significant results which are not predictable. How is that possible given the examples above? Simple: the examples may have been cherry picked to make the point. In particular, their significance (to us now) is seriously damaged by the fact that they are not general statements but are statements about a time and place. While they may be generalizable to the present day while preserving their truth, they may not be. We just do not know. So, as they stand, they are not that useful to us now.

Social science almost certainly produces many insignificant results which are not predictable. It is easy enough to come up with questions which we can then methodically answer by gathering data. What percentage of Massachusetts residents like Fig Newtons? Is it higher or lower than the percentage of New York residents who like Fig Newtons? This is certainly a question that can be asked, and one whose answer I do not know. I could obtain a grant and then spend the grant money studying this question. But it is not a significant question, and learning its answer does not advance human knowledge in a significant way.

But what about significant results? Here's a much more important question: in general, does extreme lack of sleep tend to have any significant negative impact? This is important because if it does not tend to have any significant negative impact, then many people will find this highly useful knowledge. Many people will sleep much less.

But notice something: it is not only an important question, it is also a question which people know the answer to. And this is no coincidence. It is often hard to hide important truths about people, from people.

This is not true of all social facts. Economic facts are facts about large numbers of people interacting, sometimes very indirectly, and so are a kind of fact which people have a hard time seeing, since they only encounter small numbers of other people at any given time, so they do not see the whole.

Constant, it's odd you should choose the sleep example. What with the prospects of modafinil, which supresses the desire for sleep and aids concentration, being used as an enhancement drug, and with people practicing polyphasic sleep, (admittedly with more limited success,) where you sleep 15 min at a time six times a day, the question of what the effects of this lack of regular sleep causes is actually a very open, and very interesting one. Of course, without these modifications, lack of sleep has obvious ill effects.

pdf23ds, I don't think it's odd.

Let us grant the two points you have made (of which I am, of course, well aware, as is pretty much anyone who knows what "Digg" or "Reddit" is). In fact let's go further. Suppose that polyphasic sleep lets you do away with sleep entirely (you just blink once every four hours). Suppose furthermore that a single dose of the new drug lets you do completely without sleep without any ill effects for the rest of your life. Now look at this question and try to answer it:

"in general, does extreme lack of sleep tend to have any significant negative impact?"

The correct answer is still "yes", because even if you add up the people who have taken the drug and who practice polyphasic sleep, they make up a small minority of the whole population. Since the statement begins with, "in general", it fails to be contradicted by a small minority.

As for polyphasic sleep and the drug, you can of course prove me wrong but as far as I know, the field of social science gets little if any credit for the discovery and ongoing investigation of polyphasic sleep. From what I have read, the main investigation seems to be done by individual self-experimenters. At least, that's what's made it to the social sites. Similarly, drugs are developed by and large by scientists in the fields of biology, chemistry, biochemistry, etc., not social science, and clinical trials are performed by and large by doctors, not social scientists.

Eliezer, I don't have any contribution to make to the conversation. I just want to tell you that the last 10 or so posts from you have absolutely blown me out of my socks.

I agree - very impressive series of articles. Still just about clinging to my own socks, but they're definitely trying to get away.

What's with the nitpicking, Constant? Of course the general question has the same answer, and I'm not sure what you're trying to prove by asserting your own familiarity with the phenomena I mentioned. And I don't really have any interest in the relationship between polyphasic sleep and the social sciences--why would you think I did?

The reason I thought it odd is that there are other obvious questions that are not even close to being associated with interesting open issues in science, and yet you chose this one. Probably you weren't even thinking of those complications--they weren't relevant to your point.

Thirded - Eliezer, your posts on this blog are some of the most impressive work I've ever read. The world needs more like you.

"What's with the nitpicking, Constant? [...] they weren't relevant to your point"

I had - mistakenly as it turns out - assumed that you were obeying Grice's maxims. You were, by your own eventual admission, disobeying the maxim of relevance. That is why I misunderstood you.

Out of curiosity, which time was Yudkowsky actually telling the truth? When he said those five assertions were lies, or when he said the previous sentence was a lie? I don't want to make any guesses yet. This post broke my model; I need to get a new one before I come back.

I could only predict one out of five.

Hm, when I first read those findings, I found the first three to be as expected, the fourth to be surprising (why would blacks want racist officers?), and for the fifth I found the result to make sense but considered that I would have though the same if the opposite result had been found (soldiers don't want to abandon their friends in combat, but want to leave together afterwards). So this would seem to indicate a problem with my model, given that the findings were all false.

But, is it possible that in that demonstration, those specific findings were selected specifically because they were opposite to what people would expect? If that is the case, then my model still isn't really in error, because when examining the statements I had no real reason to believe that they were meant to fool me.

2 and 5 struck me as common sense. I see reasons for 5 to be reversed now that I know the result [yeah...], but I still don't understand why 2 is wrong. Not really the point of the question, but I do wonder...

This prompted a memory of something I read in one of my undergrad psychology books a few years ago, which is probably referencing the same study, though using two different examples and one the same as the above example (though the phrasing is slightly different). Here is the extract:

Hindsight (After-the-Fact understanding)

Many people erroneously believe that psychology is nothing more than common sense. "I knew that all along!" or "They had to do a study to find that out?" are common responses to some psychological research. For example, decades ago a New York Times book reviewer criticized a report titled The American Soldier (Stouffer et al., 1949a,1949b), which summarized the results of a study of the attitudes and behavior of U.S. soldiers during World War II. The reviewer blasted the government for spending a lot of money to "tell us nothing we don't already know."

1. Compared to White soldiers, Black soldiers were less motivated to become officers.

2. During basic training, soldiers from rural areas had higher morale and adapted better than soldiers from large cities.

3. Soldiers in Europe were more motivated to return home while the fighting was going on than they were after the war ended.

You should have no difficulty explaining these results. Typical reasoning might go something like this: (1) Due to widespread prejudice, Black soldiers knew that they had little chance of becoming officers. Why should they torment themselves wanting something that was unattainable? (2) It's obvious that the rigors of basic training would seem easier to people from farm settings, who were used to hard work and rising at the crack of dawn. (3) Any sane person would have wanted to go home while bullets were flying and people were dying.

Did your explanations resemble these? If so, they are perfectly reasonable. There is one catch, however. The results of the actual study were the opposite of the preceding statements. in fact, Black soldiers were more motivated than White soldiers to become officers, city boys had a higher morale than farm boys during basic training, and soldiers were more eager to return home after the war ended than during the fighting. When told these actual results, our students quickly found explanations for them. In short, it is easy to arrive at reasonable after-the-fact explanations for almost any result.

Source:Pass, M. W. & Smith, R.E. (2007) Psychology:The Science of Mind and Behavior (Third Edition). McGraw HIll: Boston, pages 31-32

In hindsight, I guess I must have known that it would be a good idea to hang on to my undergrad textbooks. Or did I?

I believed the first two, one out of personal experience and the other out of System 1. I guessed that as a soft, water-fat intellectual, I'd have more trouble adjusting to a military lifestyle than someone who's actually been in a fight in his life. And that people from warmer climes deal with warmer temperatures more easily, well, I guess I believe people adapt to their circumstances. People from a warmer climate might sweat more and drink more water, or use less energy to generate less heat, whereas a man in Siberia might move more than is strictly necessary to keep his body temperature stable.

The other three are in subjects I know nothing about, and therefore I couldn't have predicted them. A wise man knows his limits...

New here, so hoping for (a) an answer, even though it's been a long time and (b) some mercy if I'm completely wrong... :)

Correct me if I'm wrong, but no theory based on known materials could predict what would happen to a completely new material with unknown qualities. If someone would design Kryptonite, which under the same conditions turns into water, this theory would completely fail to predict this.

Of course, you could update your theory to include Kryptonite, but it still would not include Zeptonium, which under the same conditions gives out gamma-rays.

Ridiculous, yes, but no more so than the conditions which would lead Eliezer to believe 2+2=3...

After getting miffed by your plethora of retractions, I figure that someone, at some point, left out some statistical significance values.

number 2 is the only one i'd currently be willing to bet on being correct-but now I'm thinking about how soldiers go through boot camp, weakening the effect, and maybe whoever set up the study forgot to make sure the observers didn't know whether they were observing a southern soldier or a norther soldier....

I read a few of the sequences now (including this one), and started to find that:

A: They were very interesting to read. B: They seemed a bit obvious, like common sense.

This was somewhat confusing, as things which really are obvious are very familiar and predictable, and thus, not so interesting to experience.

It's only my second time reading this (and first time reading the italics Exploring Social Psychology italics excerpt italics, that I've come to appreciate a link between sufficient explanation and illusion of obviousness.

So keep on dropping in hyper-links to previous sections like you do, they're really helpful.

p.s. The help tables' section on italics was not quite so good, as I've refrained from editing the result in order to demonstrate.

First time around (with hindsight bias) I answered F, T, F?, T, T

Second time around (without hindsight bias) I answered F, T, T?, T, F

1. Educated people are more likely to agree with authority, because they have spent more time being conditioned to obey teachers. I generalized that they might also take orders easier in the military, and conform to the circumstances easier, despite "rough and tumbled" blue collar stereotypes.

2. I thought be difficult to measure, but that there would be some small but probably measurable advantage.

3. I couldn't really tell. At first my guess was based on the idea that repressed people are more motivated and fight harder. When I reversed my decision, it was because I put a higher weight on the situation being similar to women in business, where men are more likely to rock the boat and ask for a higher salary or promotions than women are. In retrospect, both of these are attempts to confirm a hypothesis, rather than to disprove it.

4. People often favor members of their own group. Unless a majority of southern blacks dislike a majority of southern whites, rather than just being indifferent, I hypothesized that they would relate to them more easily as fellow southerners.

5. Initially, I presumed what I thought was the simple and obvious answer, that people would avoid stress. After that, I recalled that adrenalin, deep bonds of sharing an experience, and a sense of purpose are play a big part, and that boredom may actually be a bigger factor since soldiers wouldn't want to abandon their countrymen.

It's hard to describe the different sensations of the two thought processes. I think it was harder to put in as much effort when I was actively suspending my disbelief. I was just going through the motions. The second time, I was really unsure, and took a deeper look. Or maybe I would have taken a deeper look if I had reexamined it under some other pretense.

I wasn't sure whether the recession statement was true. I believe it is, but I'm not sure it would be for a full scale depression, since if people are earning less then they won't be able to be more thrifty, because they will always need to eat and afford the basic necessities.

I "got" 2/5 of the above, before reading they were inverted.

When I took a psychology survey course in college, Dr. John Sabini gave a lot of attention to social psychology experiments, and much of the class was very surprised at their results; they didn't say they "would have predicted them." Of course Sabini may have been cherry-picking results that were likely to surprise. But I've seen it claimed elsewhere that social psychologists in the '60s were largely preoccupied with producing results that would grab a lot of attention by being counterintuitive.

This hurts my image of Freud. Of course, after I have a dream about skyscrapers, he can explain that it's connected to my love of my phallus, but could he predict my love of my phallus based on a dream about skyscrapers?

It seems to me that the paraphrasing in parentheses is also preying on the Conjunction Bias, by adding additional detail.

The link to Meyer's excerpt has been dead for two years, here's an archived link: https://web.archive.org/web/20170801042830/http://csml.som.ohio-state.edu:80/Music829C/hindsight.bias.html

Strongly believed the reverse on 1 and 4, and had very little belief either way on the rest. But it was enough that I began to suspect they were all false, perhaps also the big white space beneath it tipped off my subconscious to such a possibility. Can't find the paper on sci-hub. What are the answers?

Interesting experience: I attempted to read the sequences ~10 years ago but kept getting sidetracked and put out of order by clicking all the links. This time, I decided to try again, but forced myself to read each post in order. All this to say that I read this post chronologically close to after reading "your strength as a rationalist". I can't evaluate how relevant this fact is, but I had alarm bells ringing in my head when reading the statements 3, 4, and 5. 4 especially was so incoherent to my model that I immediately thought there had to be a trick. Basically, my model:

• could argue either side for 1 with equal probability
• gave a >70% probability to 2
• would have predicted <20% for 3
• <5% for 4
• <30% for 5

I'm not certain of how I did the first time I read this post, but I'm quite certain I didn't do as well. So I'm wondering if I've gotten stronger or if it's due to the reading order.

Solidier

Misspelled.