Gary Wolf and I have a post on Boing Boing today about how Dennis Mangan cured his mom’s Restless Legs Syndrome. I mentioned this accomplishment earlier. Mangan’s story is an example of what I call personal science — doing science yourself about something you care about.
More One comment on Boing Boing is that niacin is also known as Vitamin B3 and if we searched “restless legs syndrome AND Vitamin B3″ we’d get lots of hits. I tried that search and got zero hits.
I learned something from the comments on my preventive stupidity post (also here). The best comment was from Kim Oyhus, whose earlier comment had started it all. Were I to discuss the subject from scratch, here’s what I’d add (mostly elaborating what Kim said):
Scientific discussions are usually about data and theory. From Data A, someone has “concluded” — more precisely, raised the plausibility of — Theory X. At this point, preventive stupidity often begins: Someone says “correlation doesn’t equal causation” or “the plural of anecdote is not data” or something similar.
Here’s what I think. More data are better. Two data sets are better than one. To go from one data set (A) to two (A and B) is a step forward. Less data are worse. To go from one data set (A) to none is a step backward. If you respond to the assertion that A supports X by mentioning more data that bears on the truth of X, that’s a step forward. The more convincing the new data (in either direction, pro or con), the bigger the improvement.
Likewise, more ideas are better. Two plausible explanations of A are better than one. To go from one idea (X) to two (X and Y) is a step forward. Fewer ideas are worse. To go from one explanation (X) to none is a step backward. If you respond to the assertion that A supports X by mentioning another plausible explanation of A, that’s a step forward. The more plausible the new explanation, the bigger the step forward.
The sayings I wrote about (e.g., “absence of evidence doesn’t equal evidence of absence”) make their users stupider because they push them from thinking about one data set to thinking about none (they dismiss Data A) or from considering one idea to considering none (they dismiss Theory X). They make the rest of us stupider because they prevent their users from making useful contributions. They really are preventive stupidity, as Orwell said.
If these sayings were used as transitions, as throat-clearing, fine. If somebody wrote, “Look, correlation doesn’t equal causation. Here’s another plausible explanation for what you observed . . . ” that would be okay. In my experience, that’s not what happens. They’re used to support an overall dismissiveness. Several months ago I wrote about my observations that connected socks with foot fungus. Some of the comments provided new relevant data — steps forward. A few comments, however, made this or that preventive-stupidity point (“ Sample size of 1, no control . . . . you can’t seriously think you’ve proved anything here“, “ your post is post hoc ergo propter hoc reasoning“). The comments didn’t go on to make a step forward. They were steps backward.
Thanks to Anne Weiss, Tom George, and JR Minkel
Professional scientists mostly ignore the slogans (e.g., “absence of evidence isn’t evidence of absence”) I discussed in my previous post. For example, the professional-scientific conclusion that smoking causes lung cancer came mostly from correlations. This conclusion was criticized, sure, but not by saying “correlation does not equal causation”.
Professional scientists have a much worse problem, which is that they criticize much more easily and fluently than they praise. (Marginal Revolution is an excellent blog partly because it doesn’t suffer from this.) This can be depressing (lots of work is underappreciated), exciting (anyone who sees this has a big advantage), or merely amusing, as in this example to which Stephen Marsh drew my attention:
I just returned from the MS4 conference. It is the fourth year that a group of philosophers of science have gathered to try to tease apart the implications of computer simulation in science. . . .Several presentations gave harsh criticism of climate science models. Bayesian tools (a statistical technique) were given some especially harsh criticisms. Everyone agreed the models were problematic in some sense or another. That the results were subject to all kinds of errors and suspicions, and there were substantially difficult difficulties to sort out. . . . Despite this, everyone concurs the models are robust . . . No one disagreed that the planet was warming.
The poor ability of professional scientists to praise means that comparison of A and B (two theories, say, or two experiments) mainly consists of comparing how much A and B have been criticized. How much A and B would have been praised, had scientists been better at praise, is unknown. This is a very poor way to compare stuff. Inability to praise also means that there is too much criticism. In my experience, scientists have trouble separating serious criticisms from trivial ones. For example, that climate-change models haven’t been shown to predict correctly is a serious criticism not emphasized enough (e.g., at the MS4 conference).
In the world of Orwell’s 1984,
To the end of suppressing any unorthodoxy, the [ruling] Party inculcates self-deceptive habits of mind to the inner and outer members, thus crimestop (“preventive stupidity”) halts thinking at the threshold of politically-dangerous thought.
Three sayings popular in scientific discussions show that in our world, preventive stupidity exists — and works. In a comment, Kim Ayhus has brought my attention to this.
1. Absence of evidence is not evidence of absence. Ayhus explains why this is wrong. That such an Orwellian saying is popular in discussions of data suggests there are many ways we push away inconvenient data.
2. Correlation does not equal causation. In practice, this is used to mean that correlation is not evidence for causation. At UC Berkeley, a job candidate for a faculty position in psychology said this to me. I said, “Isn’t zero correlation evidence against causation?” She looked puzzled.
3. The plural of anecdote is not data. How dare you try to learn from stories you are told or what you yourself observe!
Orwell was right. People use these sayings — especially #1 and #3 — to push away data that contradicts this or that approved view of the world. Without any data at all, the world would be simpler: We would simply believe what authorities tell us. Data complicates things. These sayings help those who say them ignore data, thus restoring comforting certainty.
Maybe there should be a term (antiscientific method?) to describe the many ways people push away data. Or maybe preventive stupidity will do.
Yesterday I attended interviews of Tsinghua students who want to transfer from another major to psychology. Almost all of it was in Chinese, but at one point, as part of an explanation of her interest in psychology, a student said (in English), “Psychology is the bridge between art and science.”
Well put. Maybe she read that somewhere, but I doubt it. I’d never heard it before. Notice how we think art can be done by anyone yet science can only be done by scientists (in extreme cases, only by physicists). Psychology, especially self-experimentation, may lead us out of that desert.
A girl sitting near me in this Beijing cafe is using a Sony Vaio Series X notebook. I’m blown away how thin and light it is. It cost about $1100 and has a 60G hard drive. Another girl near me is using an iPad, big and clunky by comparison.
At the risk of being extremely self-centered, my self-experimentation is related to this depressing news:
The decline of [America’s] estimated 2.4 million beehives began in 2006, when a phenomenon dubbed colony collapse disorder (CCD) led to the disappearance of hundreds of thousands of colonies. Since then more than three million colonies in the US and billions of honeybees worldwide have died and scientists are no nearer to knowing what is causing the catastrophic fall in numbers.
The number of managed honeybee colonies in the US fell by 33.8% last winter.
The bees vanish from the hives. What has surely happened is that their navigational systems have malfunctioned. Bees have dozens of things that must work for them to live, all of which need a certain environment. The bees live in a degraded environment. Which system will fail first? A neural system turns out to be the most sensitive to environmental degradation.
No one predicted this, nor did I predict that my self-experimentation would find many ways in which our environment, like the bees’s environment, has come to lack crucial stuff. But one reason for the two outcomes (colony collapse disorder, discoveries of my self-experimentation) is the same: The nervous system is especially sensitive to the environment. I’ve studied stuff controlled by the brain: sleep, weight, mood, arithmetic. Just as bee brains are the first part of bees to be crippled by a bad environment, our brains are the first part of us to improve when given a better environment.
In a previous post I wrote about one of the silliest letters ever signed by a group of very smart people. At the end of my comment, I wrote:
If a letter from 100 United States Senators was full of spelling and grammar errors, would you trust it?
The letter was written by Peter Gleick, a MacArthur Prize winner. In a follow-up essay in the Huffington Post, he twice called ice floes “ice flows” (“there really are polar bears on ice flows”). Who says life doesn’t imitate art?
A long list of National Academy of Science members, including several Nobel Prize winners, have published a letter in Science supporting the idea that humans have caused/will cause serious global warming. The letter is striking in several ways — how preachy it is, how it overstates its case, how it fails to provide evidence, and how it ignores the main arguments of skeptics (at least, intelligent skeptics).
It begins:
All citizens should understand some basic scientific facts. There is always some uncertainty associated with scientific conclusions; science never absolutely proves anything. When someone says that society should wait until scientists are absolutely certain before taking any action, it is the same as saying society should never take action.
“Citizens”, huh? This might interest third-graders; if they think that the brighter skeptics or most readers of Science don’t know these “basic scientific facts” they are mistaken.
The letter goes on to claim that the idea that humans are seriously warming the planet is as well established — at least, in the same category of firmly-established theories — as the conclusion that “today’s organisms evolved from ones living in the past”. That is an overstatement.
And the letter ends with hand-waving. In place of evidence that supports what they claim, they simply repeat the claims in detail (e.g., “Natural causes always play a role in changing Earth’s climate, but are now being overwhelmed by human-induced changes”).
The letter is unintentionally revealing. Here’s what I would consider reasonable evidence for serious human-generated global warming:
No. 1 isn’t clearly true; the Medieval Warm Period appears to be as warm as now. (Mann et al. understood this point; they tried to diminish the Medieval Warm Period.) No. 2 isn’t clearly true. For example, the 1930s may have been as warm as recent decades. No. 3 isn’t true. Models such as Hansen’s haven’t been shown to predict correctly. There’s no reason to take them seriously.
So No. 3 is off the table (current models are untrustworthy). That leaves Nos. 1 and 2, the failure of which to be clearly true points in the direction of no serious human-generated warming. If a theory makes two predictions, both of which appear wrong, it would be wise to start doubting the theory rather than lecture the rest of us on “basic scientific facts”.
This line of reasoning (ask whether the humans-have-caused-serious-warming idea makes correct predictions) isn’t complicated or obscure but does require you think for yourself rather than accept what you’re told. Apparently no one in this long list of distinguished scientists has done so.
If a letter from 100 United States Senators was full of spelling and grammar errors, would you trust it? Well, no . . . and you might wonder about a world with such a poorly-educated ruling class.