Month: September 2007

My Theory of Human Evolution (the pleasure of crafts)

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On the Meet the Pros episode of This American Life, David Rakoff said

I make stuff: boxes, lamps, mirrors, small folding screens, painted jackets for kids, that sort of thing. It’s what I do in my spare time. Some people exercise; my salvation lies in time spent alone with an Xacto knife and commercial-grade adhesive. During the act of making something, I experience a kind of blissful absence of self and a loss of time. I almost cannot get this feeling any other way. . . . I once spent 16 hours making 150 wedding invitations by hand and was not for one instant of that day tempted to check the time.

He gives the stuff he makes as gifts to his friends. A Martha Stewart Living staffer tells Rakoff it is harder to do this sort of thing for a living than as a hobby.

My theory of human evolution, which explains how we became the only species whose members make their living in many diverse ways, says the sequence was: 1. Hobbies. 2. Part-time jobs. 3. Full-time jobs. The first hobbies obviously involved making things and were the beginnings of craftsmanship. That many of us, such as Rakoff, enjoy crafts indicates that those early genes are still there.

Before trading evolved, you gave the products of your specialized skill to your friends, which generated a vague obligation. This was the precursor of trading. In contrast to trading, of course, in this case the recipients may have only a little use for what they receive.

Leonard Syme on Teaching

Seth Roberts1 Comment

In a recent post I described an amazingly influential class on epidemiology taught by Leonard Syme, a professor in the UC Berkeley School of Public Health. Andrew Gelman (”inspiring”) and Matthew Henty (”THIS is how to learn”) were impressed. To find out more about the class, I asked Syme a few questions:

1. What gave you the idea of teaching the course this way?

I was struck by the fact that we can’t do classic experiments in epidemiology. We can’t assign one randomly selected group of babies to be smokers for the rest of their lives and another random group to refrain. Instead, we have to study people as we find them (in religious groups, in jobs, in various locations, marital statuses, etc) and then try to statistically adjust for the things we think might be confounders. In general, we end with evidence that is not very good and the burden on us is to assess the data very, very carefully. I have defined epidemiology as the the activity of evaluating lousy data as best we can. The class merely illustrated this issue. The theme of the class was how can so many bright and caring people come to such different conclusions looking at basically the same data. The lesson was that we really needed to be clear about our biases and expectations and that we needed to think about the data as carefully as possible. I thought the class should have been called “The Sociology of Knowledge”.

2. What were a few of the accepted ideas that you covered?

a. Everyone knew that high fat diets were related to serum lipids and coronary heart disease. The data then (and now) do not support that belief.

b. Everyone knew that the surgical treatment of breast cancer required radical surgery. There was a rumor that lumpectomy would do as good a job but few people believed that. The evidence showed that a more limited procedure was just as good.

c. Some people had been calling for research on the relationship between race and IQ. Majority scholars argued that no good could come from such research and they were refusing to fund such work. How do we decide what is worth studying? Because there might be harm?

d. A major national clinical trial on the treatment of diabetes showed no results but it turned out the randomization procedures were seriously flawed. People in the treated group consistently had higher risk factors to begin with and this doomed the trial. How do we take account of the fact that randomization is a method and not a result. Unbalanced randomization results will occur with a
predictable regularity. This study led to the idea of stratification in sampling.

e. Everyone knew that multiphasic screening was good to do. It detected disease early. The evidence did not support this. The evidence showed that early detection means you live longer with the disease but you still die on Thursday morning at 10 AM. You just knew about it longer.

There were 10 sessions like this. Three hours each! Students (n = 15-20) had to read hundreds of pages each week and had to present their case with great frequency – probably 3 or 4 times during the semester. The only rule for presentations was that people could not summarize the papers. Everyone had already read everything and they had to get on with the argument.

3. How long did you teach the course? Did the course change over the years? If so, how?

I taught the course for 12 years. It changed each year only because I updated the literature on particular issues and because I found a new issue that I thought might be more interesting than one of the older topics. But the way in which the course was organized did not change.

4. Apart from lots of epidemiology, what did you learn from teaching the course? For example, did you learn anything about teaching?

I’m not sure. As a teacher, my emphasis has always been on challenging people to think hard about issues. My favorite definition of a good book is one that forces you to do your own thinking. When I lecture, I get very nervous when I see people taking notes. What are they writing? What I’m saying? Not good. Unless they are writing things down so that they can refute my points later on.

Can Professors Say the Truth? (letter from Willow Arune)

Seth Roberts9 Comments

Willow Arune, a retired lawyer who has been one of Michael Bailey’s supporters, sent me this email:

Hi Seth,

I have found your exchanges with Deirdre McCloskey rather amusing.

I am one of those transsexual women who supported Bailey. I did so publicly and as a result was subjected to the lies, half-truths and innuendo of Andrea James and Lynn Conway. Even now, the slander is still on both of their web pages. Along the way, I noted that Dr. McCloskey had announced that she would sue Bailey if he dared to suggest that she was “one of those” so I did it for him. Frankly, her autobiography does that to her as well, although she does not use the term

I invited Dr. McCloskey to sue me. I even wrote her lawyer providing an address for service. For one week, I wrote her daily asking her to please, please sue me. Years later, she has still not done so. A shame really as I had lined up a wonderful cast of potential witnesses to provide expert testimony. Truth is always a defence to such silly actions.

Dr. McCloskey has hidden behind the more overt actions of Andrea James and Lynn Conway. Yet she was one with them, an equal participant in the vile and ugly attacks made not only on Bailey but also on other transsexual women who dared to support him. As Dr. Dreger points out, many would not allow their names to be used for fear of attracting attacks from McCloskey’s crew. I also received many letters of support from transsexual women who agreed with Bailey or, at the least, thought the actions of Conway, James and McCloskey were repugnant. None would dare have their comments public for fear of being subjected to the same attacks that had been made against other transsexual women and myself.

Let me give you one example of those actions that McCloskey supported, those actions she says do not cause her shame.

Firstly, I am a rape survivor. Andrea James was well aware or this as we had continued a “back channel” correspondence well after Bailey’s book was published. During 2003, on a public newsgroup, an anonymous writer posted a vile accusation that I was a “registered sex offender”. Not true then or now. Then, on December 24th of that year, I received a post from Andrea James asking me to “confirm or deny” that I was a registered sex offender. In the same post, she threatened to send out “investigators” to look into my past. She justified this action by the broad premise that her end justified any means and that those of us who supported Bailey must have ugly reasons to do so in our past. She would discover those and expose us.

Her web page on me followed, as did another screed from Lynn Conway. Lies, half-truths and innuendo.

This tactic – the no-name post to an e-group or newsgroup – was repeated in the case of the Transkids. It started with a further anonymous post, this one to an e-group on Calpernia Addam’s web site. I first heard of it on an e-group for UK transsexuals and complained to the moderator. In time, thanks to confirmation from other transgendered people, Christine Burns issued a formal apology for spreading the lies, the day after she was awarded an MBE. She had, she stated, relied upon a “usually reliable source” (Andrea James).

The tactic is straight from the McCarthy days. Spread an unfounded accusation and repeat it often so that some will believe it is true. As the writer Patricia Cornwell has recently shown, even one with many financial resources cannot control a slander on the Web.

Ms. James attacked several transsexual women who dared to either support Bailey or Blanchard, or even those who simply wanted to turn down the heat. Each was (and remains) subjected to a web page on Andrea’s site. No wonder few were willing to step out of the trenches. Most transsexual women simply wish to get on with life. They do not wish to be vilified – and outed – on a web page available to anyone with a computer.

If Dr. McCloskey is not ashamed of this type of tactic, as she states, she should be. Instead, she continues to attack you and anyone who dares to express even the slightest question about Blanchard’s theory or the means used by Conway and James to attack Bailey and anyone else who crosses their sights.

It is part of this nasty group to ignore the theory and go personal. In the years since Bailey’s book has been published, I have had few conversations or exchanges about “the theory”. The hate mail that arrives in my mailbox always quotes some of the accusations made by James or Conway about me as a person. James’ screed is copied and posted to some newsgroups on a regular basis by her supporters. Nor, after all this time, have I met any transsexual who has directly suffered as a result of Bailey’s book – and I have asked repeatedly for one to come forward.

The book was published several years ago; I have certainly moved on. I stood up for Dr. Bailey’s right to publish and against the vile and arrogant tactics of Conway, James and McCloskey. I am glad that Dr. Dreger had the courage to expose the facts concerning this matter. As both James and Conway see fit to retain their personal attacks on me on their respective web pages, I can now point to Dr. Dreger’s article as some vindication, certainly as an explanation. In these days when potential employers even check e-groups and such regarding potential employees, slander of the type employed by Conway, James and McCloskey against other transsexual women can have dramatic effect. A dispute over a theory is not a reason to slander a person in the manner employed by these zealots.

Willow Arune

Her blog.

A Clinical Trial of Fish Oil

Seth Roberts1 Comment

A big study of the effects of fish oil is taking place at Ohio State University. From its website:

The beneficial effects of fish oil (or eating fish more frequently) include reductions in triglycerides, blood pressure, and heart rate, as well as increases in HDL cholesterol, the “good” type of cholesterol. In addition, certain aspects of immune function also appear to show favorable responses to fish oil supplementation, and some studies suggest that fish oil helps to improve mood and decrease depression. This study is designed to examine how supplementation with omega-3 polyunsaturated fatty acids (key fish oil components) affects aspects of your immune response, and your mood; because some research suggests that people who eat more fish may do better during stressful times, the study will also examine how fish oil affects your immune response to stress, certain stress hormone responses, and your psychological response to stress.

I was especially curious how they are measuring brain function. Here’s how:

At Visit 1 and Visit 5 [16 weeks after Visit 1] only, you will be asked to perform various tasks for about 20 minutes; these will include making a short speech and computing arithmetic problems without pencil or paper in the presence of other research team members. You will be audiotaped while you complete these tasks. . . At Visit 1 and Visit 5 only, the researchers will administer short tests that measure aspects of memory and concentration to see if the fish oil supplements have positive effects on learning and memory. For example, you might be asked to memorize several words, and then you would be asked which of the words you remember several minutes later.

Each subject participates for 24 weeks. The study, which started in 2006, is supposed to end in 2010, with 138 subjects in two groups (69 per group).

Tyler Cowen’s experience with flaxseed oil implies that omega-3 supplementation can dramatically reduce inflammation within a few weeks. My research shows that omega-3 supplementation can improve brain function within a few hours. This study appears to be much larger than necessary.

Janet Malcolm on Email

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Janet Malcolm is the most divisive (within me) writer I have encountered. I loved The Journalist and the Murderer. A journalistic masterpiece (except for the opening sentence about all journalists being con artists). I wrote her a fan letter about it. I hated In the Freud Archives, her hit piece about Jeffrey Masson. This review of a book about how to write email is not very good, alas. Too obvious. How far the gifted have fallen.

Jeffrey Masson used to live in Berkeley. I visited him while writing an article for Spy about his lawsuit against Malcolm (it never ran). While I was there, he got a phone call from Joe McGinness, the “journalist” of The Journalist and the Murderer.

How Accurate is Epidemiology? (part 4)

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In Sunday’s NY Times Magazine, Gary Taubes argued that epidemiology does not provide a good basis for health decisions — it is often wrong, he claimed. By “wrong” he meant experiments were more pessimistic. Things that seemed to help based on surveys turned out not to help, or help much less, when experiments were done. A 2001 BMJ editorial disagrees:

Randomized controlled trials and observational studies are often seen as mutually exclusive, if not opposing, methods of clinical research. Two recent reports, however, identified clinical questions (19 in one report, five in the other) where both randomized trials and observational methods had been used to evaluate the same question, and performed a head to head comparison of them. In contrast to the belief that randomized controlled trials are more reliable estimators of how much a treatment works, both reports found that observational studies did not overestimate the size of the treatment effect compared with their randomized counterparts. . . . The combined results from the two reports indeed show a striking concordance between the estimates obtained with the two research designs. . . . The correlation coefficient between the odds ratio of randomized trials and the odds ratio of observational designs is 0.84 (P<0.001). This represents excellent concordance.

Here is the data:

experiment vs observation

The correlation coefficient is the wrong statistic. They should have reported the slope of a line through the points constrained to have intercept = 0. The graph above shows that the slope of such a line would be close to 1. Unlike the correlation, that is relevant to their main question — whether surveys tend to find larger risk ratios than experiments.

Part 1. Part 2. Part 3.

Addendum: A later (2005) paper by John Ioannidis, one of the authors of the 2001 paper, claims to explain, in the words of its title, “why most published research findings are false.” The above data suggest that most published research findings in Ioannidis’s area are accurate. Alex Tabarrok on the 2005 paper.

Spider Science

Seth Roberts3 Comments

The success of my self-experimentation has puzzled me. The individual discoveries (a new way to lose weight, a new way to improve mood, sleep-related stuff, the fast effects of omega-3) seem normal; someone would have found them. It’s their combination that’s strange. Scientists who study weight control do not discover anything about mood, for example. But I did.

An ancient (2001) essay by Paul Graham is about how the future lies with web-based applications. No more Microsoft Word. One of Graham’s stories sheds light on my puzzle:

I studied click trails of people taking the test drive [of Graham’s web-based application] and found that at a certain step they would get confused and click on the browser’s Back button. . . . So I added a message at that point, telling users that they were nearly finished, and reminding them not to click on the Back button. , . . The number of people completing the test drive rose immediately from 60% to 90%. . . . Our revenue growth increased by 50%, just from that change.

I studied click trails. He examined a rich data set, looking for hypotheses to test. I practiced what I’ll call spider science: I waited for something to happen. When it did, I started to study it, just as a spider moves to the part of the web with the fly. Here are examples:

1. A change in what I ate for breakfast caused me to wake up early much more often. I did many little experiments to find out why.

2. Watching TV early one morning seemed to have improved my mood the next day. This led to a lot of research to figure out why and how to control the effect.

3. After I started to stand more, my sleep improved. I made many measurements to see if this was cause and effect and if so what the function looked like (the function relating hours of standing to sleep improvement).

4. In Paris I lost my appetite. This started the research that led to the Shangri-La Diet.

5. The morning after I took some omega-3 capsules, my balance improved. This led to experiments to see if it was cause and effect and if so what the function (balance vs. amount of omega-3) looked like.

6. One day I took flaxseed oil at an unusual time. My mental scores suddenly improved. I started to study these short-term effects.

7. While studying these short-term effects, I noticed improvements shortly after exercise. I started to study the effect of exercise.

Graham studied click trails partly because he could so easily act on anything he learned, partly because it was his company and he was so committed to its success. The seven examples I have given all came about partly because I could easily act on what I noticed and partly because I would directly benefit from learning more.

Conventional scientists do not practice spider science. They do not continuously monitor or search out large rich data sets hoping to find something they can act on. They can’t afford to, it’s unconventional, it’s too risky, it won’t pay off soon enough, they probably couldn’t act on what they found, etc. Later in Graham’s essay he marvels that big companies develop any software at all. Microsoft is like “a mountain that can walk.” Likewise, I’m impressed that scientists operating under the usual constraints manage to discover anything. You might think tenure allows them to relax, wait, take chances, and do things they weren’t trained to do, but it doesn’t work out that way.

How Accurate is Epidemiology? (part 3)

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To my previous post about Gary Taubes’s NY Times article, Andrew Gelman adds that it is good to see public discussion of these issues. I agree. I also like seeing them raised in a dramatic context: Who’s right? Powerful people making serious mistakes. How will we know? Health at risk! That sort of thing.

Speaking of drama and epidemiology . . . For many years the introductory epidemiology class for graduate students in the UC Berkeley School of Public Health was taught by Leonard Syme. I learned about this class at party. I spoke to someone who had taken it and, as a result, had switched from public policy to epidemiology. Very impressive. I knew Syme slightly. I went to his office to learn more about how he had managed to influence someone so much. “Lots of students have said that,” he told me as I entered his office. Lots of students, after taking his class, had decided to become epidemiologists. The list included Michael Marmot, one of the most important epidemiologists in the world, who studies the social gradient in health — the tendency for the people at the top to be healthier than the people at the bottom, even after controlling for all sorts of things.

The class met once/week. Every week there was a new topic. For every topic Syme would assign a paper laying out the conventional wisdom — that high cholesterol causes heart disease, for example — plus three or four papers that cast doubt on that conclusion. I think he even had American Heart Association internal emails. Several students would present the material and then there would be debate — what’s to be believed? The debates were intense. If ever the students seemed to be reaching agreement, he would say something to derail it. “You know, there was a study that found . . . ”

Practically all classes make you think you know more at the end of them than you knew when they began. Practically all professors believe this is proper and good and cannot imagine anything else. With Syme’s class, the opposite happened: Your beliefs were undermined. You walked out knowing less than when you walked in. You had been sure that X causes Y; now you were unsure. At first, Syme said, many students found it hard to take. A three-hour debate with no resolution. They did not like the uncertainty that it produced. But eventually they got used to it.

The overall effect of Syme’s class was to make students think that epidemiology was important and difficult — even exciting. It was important because we really didn’t know the answers to big questions, like how to reduce heart disease; and it was difficult and exciting because the answers were not nearly as obvious as we had been told. This is why many students switched careers.

Marmot on Syme: “I have never come across anyone in the academic world who had quite the powerful influence on students that Syme did.” Nor have I. That meeting with Syme, about five years ago, was one of two conversations in my life that really taught me something about how to teach. I was the only person at Berkeley to ever ask him about his teaching, Syme said. What a pity.

Syme on how his research began.

Fear-Mongering?

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This post by Dr. Erika Schwartz, complaining about a breast cancer story in the NY Times, makes important points. When politicians — such as Joe McCarthy or Jean-Marie Le Pen — try to scare us, most of us appreciate the psychology involved: The more fearful we become, the more we will look to them to protect us, thus increasing their power. Our fear = their power. Schwartz is saying that respected doctors and journalists do the same thing. How prophetic was The Coming Plague (1994) by Laurie Garrett?

Schwartz’s post has too little detail to convince me that this particular story is guilty. Nor do I agree with her that statistics are “totally meaningless when applied to the individual.” Her contribution is to ask: how can we discuss these issues without fear-mongering?