Wellcome Collection in London has exhibition on human augmentation
If you live in London, it might be of some interest to you.
Simple theory of IMDB bias
IMDB top 250 list is dominated by old movies, which conflicts with my perception (shared by majority of people as far as I can tell) that new movies are far better than old movies (comparing either top with top or average with average).
I have a simple theory why IMDB is wrong:
- For new movies, very wide population have seen it, many not fans of the genre. They vote on IMDB soon after watching.
- For old movies, only narrow population of fans have seen it recently. The only people who vote on IMDB are those who've seen it recently (atypical fans), or have particularly good memories of it (atypical fans again). People who watched an old movie ages ago but don't remember much about it are very unlikely to vote on IMDB.
- Therefore it's much more difficult for a new movie to get a good IMDB score than it is for an old movie.
- Therefore a new movie with identical IMDB store is likely much better than an old movie with identical score.
Can You Build a Better Paper Clip?
Nice article about paperclip industry, I'm sure it will be of considerable interest to many LessWrong readers.
Genes are overrated
This is hardly news, but this Guardian article reminded me of it - genes are really overrated, both among unwashed masses, and also here on Less Wrong.
I don't want to repeat things which have been said by so many before me, so I'll just link a lot.
Summary of evidence against genes being important:
- Almost no genes correlating with anything interesting been found. This is totally crushing evidence. If genes were important, Bayesian surprise of this lack of results would be in the land of impossible.
- Massive very fast changes of various supposedly highly hereditary characteristic with time in same populations. To name a few - Flynn effect, changes in people's height, obesity epidemic.
- Plenty of evidence of very large very reliable associations of various environmental factors with various important outcomes. For example unlike with genes and cancer where we get just noise, we know very well how much smoking increases chance of lung cancer.
Summary of evidence for genes being important:
- Some twin and adoption studies - which rely on very tiny highly atypical samples and a lot of statistical manipulation to get results they want. To make matters worse, results they got were wildly inconsistent.
And there's nothing more. Decades ago, before we had direct evidence of lack of correlation between genes and outcomes, it was excusable to believe genes matter a lot, even if it was never the best interpretation of data. Now it's just going against bulk of the evidence.
And in case you're wondering how could twin studies show high heredity when everything else says otherwise, I have two examples for you.
This one from a critique of twin studies by Kamin and Goldberger:
"A case in point is provided by the recent study of regular tobacco use among SATSA's twins (24). Heritability was estimated as 60% for men, only 20% for women. Separate analyses were then performed for three distinct age cohorts. For men, the heritability estimates were nearly identical for each cohort. But for women, heritability increased from zero for those born between 1910 and 1924, to 21% for those in the 1925-39 birth cohort, to 64% for the 1940-58 cohort. The authors suggested that the most plausible explanation for this finding was that "a reduction in the social restrictions on smoking in women in Sweden as the 20th century progressed permitted genetic factors increasing the risk for regular tobacco use to express themselves." If purportedly genetic factors can be so readily suppressed by social restrictions, one must ask the question, "For what conceivable purpose is the phenotypic variance being allocated?" This question is not addressed seriously by MISTRA or SATSA. The numbers, and the associated modeling, appear to be ends in themselves."
As the final nail in the coffin of heredity studies:
The Body-Mass Index of Twins Who Have Been Reared Apart
We conclude that genetic influences on body-mass index are substantial, whereas the childhood environment has little or no influence. These findings corroborate and extend the results of earlier studies of twins and adoptees. (N Engl J Med 1990; 322:1483–7.)
Or as paraphrased by a certain commenter on Marginal Revolution:
IOWs, the reason why white kids of today are much fatter than white kids of the 50s and 60s is due to genetic influences and environment has little or no influence
To summarize - heredity studies are pretty much totally worthless data manipulation. Once we accept that, all other evidence points for environment being extremely important, and genes mattering very little. We should accept that already.
Folk theories can be useful even when they're entirely wrong
Here's an interesting but very old paper - two theories of Heat Control.
It discusses mental models of home heating systems (thermostats) non-experts use.
These models tend to be extremely wrong from theoretical perspective, but surprisingly useful in practice.
The findings are applicable to a much wider range of subjects than just thermostats, and have certain epistemological significance, especially with regard to compartmentalization.
Preference utilitarian measure of historical welfare
GDP measures essentially how good we are at making widgets - and while widgets are useful, it is a very weak and indirect measure of welfare. For example UK GDP per capita doubled between 1975 and 2007 - and people's quality of life indeed improved - but it would be extremely difficult to argue that this improvement was "doubling", and that the gap between 2007's and 1975's quality of life is greater than between 1975's and hunter-gatherer times.
It's not essential to this post, but my very quick theory is that we overestimate GDP thanks to economic equivalent of Amdahl's Law - if someone's optimal consumption mix consisted of 9 units of widgets and 1 unit of personalized services - and their purchasing power increased so now they can acquire 100x as many widgets, but still the same number of services as before - amount of the mix they can purchase increased only 9x, not 90x you'd get by weighted average of original consumption levels (and they spend 92% of their purchasing power on services now). The least scalable factor - whichever it is - will be the bottleneck.
If we're unhappy with GDP there are alternative measures like HDI, but they're highly artificial. It would be very easy to construct completely different measures which would "feel" about as right.
Fortunately there exists a very natural measure of welfare, which I haven't seen used before in this context - preference utilitarian lotteries. Would you rather live in 1700, or take a 50% chance of living in 2010 or 700? Make a list of such bets, assign numbers coherent with bet values (with 100 for highest and 0 for your lowest value) and you're done! By averaging many people's estimates we can hopefully reduce the noise, and get some pretty reasonable welfare estimates.
What would you do if blood glucose theory of willpower was true?
There's considerable amount of evidence that willpower is severely diminished if blood glucose get down, and this effect is not limited to humans. And a small sugary drink at the right time is enough to restore it.
We're talking really small numbers. Total blood glucose of a healthy adult is about 5g and it varies within fairly limited range. Then there's maybe 45g in total body waters. Then there's about 100g of glycogen in liver, plus yet larger amount in muscles and other organs, but which doesn't seem to take part in sugar level regulation. For comparison a small can of coke contains 33g - a really small amounts at appropriate times can make a big difference.
This leads to two issues. First, is blood glucose a good explanation for willpower deficiency and therefore akrasia? I'd say there's significant amount of evidence that some effect exists, but is it really the most important factor? Humans are complicated, science knows very little about how we work, and probably half of what it "knows" is false or at best only half-true. Caution is definitely warranted.
And the second issue - if this theory was true - and by manipulating blood glucose levels you could achieve far greater willpower whenever you wanted, what would you do? It seems that exploiting it isn't that easy, and I'd love to hear if any of you tried it before.
Superstimuli, setpoints, and obesity
Related to: Babies and Bunnies: A Caution About Evo-Psych, Superstimuli and the Collapse of Western Civilization.
The main proximate cause of increase in human weight over the last few decades is over-eating - other factors like decreased energy need due to less active lifestyle seem at best secondary if relevant at all. The big question is what misregulates homeostatic system controlling food intake towards higher calorie consumption?
The most common accepted answer is some sort of superstimulus theory - modern food is so tasty people find it irresistible. This seems backwards to me in its basic assumption - almost any "traditional" food seems to taste better than almost any "modern" food.
It is as easy to construct the opposite theory of tastiness set point - tastiness is some estimate of nutritional value of food - more nutritious food should taste better than less nutritious food. So according to the theory - if you eat very tasty food, your appetite thinks it's highly nutritious, and demands less of it; and if you eat bland tasteless food - your appetite underestimates its nutritious content and demands too much of it.
Reference class of the unclassreferenceable
One of the most useful techniques of rationality is taking the outside view, also known as reference class forecasting. Instead of thinking too hard about particulars of a given situation and taking a guess which will invariably turned out to be highly biased, one looks at outcomes of situations which are similar in some essential way.
Figuring out correct reference class might sometimes be difficult, but even then it's far more reliable than trying to guess while ignoring the evidence of similar cases. Now in some situations we have precise enough data that inside view might give correct answer - but for almost all such cases I'd expect outside view to be as usable and not far away in correctness.
Something that keeps puzzling me is persistence of certain beliefs on lesswrong. Like belief in effectiveness of cryonics - reference class of things promising eternal (or very long) life is huge and has consistent 0% success rate. Reference class of predictions based on technology which isn't even remotely here has perhaps non-zero but still ridiculously tiny success rate. I cannot think of any reference class in which cryonics does well. Likewise belief in singularity - reference class of beliefs in coming of a new world, be it good or evil, is huge and with consistent 0% success rate. Reference class of beliefs in almost omnipotent good or evil beings has consistent 0% success rate.
And many fellow rationalists not only believe that chances of cryonics or singularity or AI are far from negligible levels indicated by the outside view, they consider them highly likely or even nearly certain!
There are a few ways how this situation can be resolved:
- Biting the outside view bullet like me, and assigning very low probability to them.
- Finding a convincing reference class in which cryonics, singularity, superhuman AI etc. are highly probable - I invite you to try in comments, but I doubt this will lead anywhere.
- Or is there a class of situations for which the outside view is consistently and spectacularly wrong; data is not good enough for precise predictions; and yet we somehow think we can predict them reliably?
How do you reconcile them?
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