Monthly Archives: May 2011

Smoking and creativity: 20th-century data

Collecting data on the smoking habits of 18th-century writers wasn’t working out so well. After going through the 20 most eminent writers on my list but only being able to find anything for about half of them (and realizing that this track record could only get worse as I moved on to the more obscure authors), I decided I needed to find a more cooperative sample.

Figuring that there would be more biographical information available for more recent figures, and that English-speaking writers would have more biographies in English, I looked at male writers from English-speaking countries (Britain, Ireland, and America) who turned 40 (or died, for those who didn’t make it to 40) between 1900 and 1950. As before, the list of significant writers comes from Charles Murray’s Human Accomplishment.

This time I was much more successful. My list includes 59 men, and I was able to find some kind of information for all but 6 of them. You can see the spreadsheet here.

I had hoped to analyze the data to see if higher levels of literary accomplishment were associated with higher rates of smoking. But unfortunately the early 20th century, unlike the 18th, seems to have been a time when just about everyone smoked. My sample includes a grand total of three, count them, three unambiguous non-smokers (Ernest Hemingway, Theodore Dreiser, and Robert Frost), plus three more (Eugene O’Neill, Graham Greene, and William Carlos Williams) who smoked but later quit. For whatever it’s worth, all three of the non-smokers are relatively eminent (scoring 15, 10, and 6, respectively, on a list where the median score is 4), but it’s hard to draw any real conclusions from such small numbers.

Another problem is that, though some are more eminent than others, everyone in my sample is an eminent writer. If I want to compare highly creative people to those who are less creative (rather than comparing the super-super-creative to the merely super-creative), I need a control group of people from the same period who did not work in a creative field. Of course, they must still be famous enough to have left behind adequate biographical information, which rather limits the choices. Athletes are out, for obvious reasons. Politicians are a possibility, but they may well have below-average rates of smoking for image-related reasons. (Certainly this is true today; I’m not sure whether it would have been true in the early 20th century.) Captains of industry could work, I suppose, if I could find a list somewhere, and if a sufficient number of them have gone down in history. I don’t have any other ideas.

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Filed under Drugs, Literature, Statistics

Tobacco use among 18th-century writers

As a follow-up to my post on smoking and creativity, I’ve compiled a list of all the significant 18th-century figures in Western literature (as listed by Charles Murray in Human Accomplishment) and am in the process of gathering information on who smoked and who didn’t.

In contrast to my previous post, I am here restricting myself to a limited time period (the 18th century)  and am considering relatively minor literary figures as well as major ones — from Goethe and Rousseau all the way down to George Farquhar and Maler Müller. The idea is to compare the major figures with the minor ones to see if tobacco use is associated with higher (or lower) levels of literary accomplishment.

I have put my data (what I have so far) on a spreadsheet here, which anyone can read and edit. So take a look, and if you happen to know anything about any of these people’s smoking habits or lack thereof, just add it to the spreadsheet. After I’ve collected enough data, I’ll put up another post analyzing it.

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Filed under Drugs, Literature, Statistics

Dream experiment methodology

In thinking about how to carry out my Dunne-inspired experiment with precognitive dreams, I’m bothered by two things.

First, there is no control group. Anyone with sufficiently sharp pattern-recognition instincts will be able to find apparent connections between events even when the events are completely unrelated and the similarities are mere coincidence. What we want to know is not whether we can find connections between dreams and future events, but whether we can find significantly more such connections than would be expected by chance — and to know how many chance connections to expect, we need a control.

But what could that control possibly be? Other dreams of mine can’t be used as a control, because the hypothesis is that any of my dreams may have a non-chance connection with any of the events in my life, past or future. One possible control would be to have two dreamers do the experiment together and see whether dreamer A’s dreams match future events in dreamer A’s life more often than dreamer B’s dreams do. This won’t really work, either, though, since naturally my dreams, more so than anyone else’s, will tend to be about the kinds of things that are in my life (sugar gliders, English classes, etc.), making even chance matches more likely.

Even if a suitable control group could be found, experimenter bias would be an inescapable problem. All the pattern recognition is done by the dreamer, who knows which events are from his own dreams and which are from the control group, and he may subconsciously try harder to find links in the one case than in the other.

As far as I can see, there is no solution to these problems. The experiment will simply have to be done without a proper control.


The second thing that bothers me is that deciding whether a particular dream event is meaningfully connected with a particular real-life event requires a subjective judgment call, again leaving the door wide open for subconscious bias.

I think I have a partial solution for this one — not perfect, but probably the best that can be expected given the circumstances. The fact that only one person has any access to the relevant data — dreams and personal experiences — makes it impossible to devise anything like a proper double-blind experiment, but we can get as close as we can.

Here’s what I propose to do: For each dream I log, I will try to come up with and record as many connections as possible with both pre-dream and post-dream waking-life events. Then I will type up an account of the dream and append, in randomized order, accounts of each of the relevant waking-life events. However, each of these events will be described as having occurred prior to the dream. If I write, “Three days before the dream, . . .,” what follows might (for all the reader knows) really be an account of something that happened three days before the dream, but it could just as well be a description of an event which occurred three days after the dream. (The actual temporal distance of the event from the dream — a day, three days, a week, etc. — will be given, but always as if in the past rather than the future.) Also, for each event, I will provide some indication of how commonly events of that sort occur in my life.

I will then send these reports to a few third parties for evaluation. (Since people who are privy to the actual details of my life would be disqualified, I will probably recruit these people online.) Each evaluator will read the account of the dream and the events and will give each event a rating between 0 (no real connection; almost certainly just a coincidence) and 3 (so obviously tied to the dream that I would be astonished to hear that the dream had come first). Averaging the various evaluators’ ratings for each event, I can get some semblance of an objective measurement of which events are closely connected to the dream and which are not. If future events get high ratings about as often as past events do, I would consider that to be evidence of precognition.

This methodology is obviously far from ideal, but it’s the best I can come up with given the slippery and subjective nature of the subject matter. If anyone has any suggestions for improvement, please leave a comment.


As an example of how this would work, here are two more real-life events which I consider to be possibly connected with the snake dream recounted in this post (read it now if you haven’t already, or reread it to refresh your memory). Rate the events in the comments, and after I have a few ratings I will reveal whether each of them happened before or after the dream.

Event A: About a week before the dream, I was playing with the three-year-old daughter of a friend. (Her mother pays me to do this for half an hour every week, and to speak to her in English while we play.) We were playing with salt dough and sculpting various things. I tried to get her to make different things — bowls, snowmen, etc. — but she was only interested in making two things again and again: eggs and worms. Often she would give me a big worm and tell me to “make it a snake” by sculpting a head to put on it. (Cf. the worm/snake in the dream, which looked as if it were made of dough.) As I said, I play with this girl regularly, but this was the first time we used dough or clay together; aside from this, I haven’t sculpted anything in a very long time.

Event B: About a week before the dream, I went to feed my mealworms and found that nearly half of them were dead (probably from overheating, since there was a sudden heat wave at that time). Live mealworms are a golden-brown color, but when they die they quickly turn black (cf. the little black worms in the dream). I usually find a few dead mealworms in the dish every day, but this was the first time I’d ever seen so many of them die at once.

For good measure, here are two more dreams, each with a connected waking-life event:

Dream C: I dreamed that I was about to go outside, but when I opened the door I saw a huge Diatryma stalking about just beyond the front porch. (A Diatryma is a huge flightless prehistoric predatory bird, something like a cross between a secretary bird and a T-rex. They are often depicted eating the dog-sized ancestors of horses. The bird is called Gastornis now, but I still think of it as Diatryma.) I quickly closed the door and went back inside. I went back several times and looked out the glass door, but every time the Diatryma was still there, and I was afraid to go out.

Event C: The day before the dream, I was tutoring a grad student in her living room, and her 9-year-old son was also there, drawing pictures on scrap paper on the coffee table. He showed me one of his pictures and explained it to me. It was “a picture of birds,” but the birds had no wings and were shown walking on the ground. They were not ostriches, though, but round-bodied birds with short necks. One of them was chasing some kind of small quadruped. When I asked him what it was, he said it was a horse.

Dream D: I dreamed that I was teaching a large English class, including one of my real-life students (I’ll call her Joan). I had just started the class, when loud music started to come from my bag. I searched through the bag and found a little travel-size alarm clock (just like one I owned years ago, before I had a cell phone), which was making the noise. I tried to turn it off but couldn’t. Finally I took out the batteries. I started the class again, but someone came in and told me I had to go to a training program right away. I apologized to the students and walked out of the class.

Event D: I was teaching a small group of Taiwanese English teachers, including “Joan.” I had just started the class when I got a text message on my phone, which made an audible beep. I checked it and found that there was an emergency at home and that I had to leave right away. I apologized to the students and walked out of the class.


Please leave a comment rating the four events as described.


Filed under Anecdotes, Dreams, Precognition / Prophecy

What counts as a precognitive dream?

I’m preparing to attempt to replicate J. W. Dunne’s Experiment with Time (as described by Bruce Charlton here and here), but before I do so, I want to try to set some kind of standard for what dreams can reasonably be considered precognitive. For example, here’s a dream which I had recently. Should it be considered prophetic?


I raise mealworms at home and feed them, among other things, stale bread which I keep in a plastic bag in the freezer. I dreamed that I took the bread out of the freezer to feed them and found that it was crawling with worms which had somehow survived in the freezer — not mealworms, which are rather handsome and clean-looking as larvae go, but short black maggoty things which really looked horrible. Most of them were quite small, but there was one larger one, striped with blurred bands of black, maroon, and deep blue, which was slithering through the bread with a motion similar to that of an aquatic snake. This big worm also looked like it had a strange texture, like marzipan or Play-Doh; its appearance and movements made me think of claymation.

I was disgusted by the wormy bread and just set the whole thing, bag and all, down in the wide shallow dish where I keep my mealworms. “There are worms in the bread,” I told my wife.

“You mean mealworms?”

“No, little black worms, and one big worm that looks like a snake but isn’t a snake.” The big worm, very big indeed now, was out of the bag and slithering very quickly, astonishingly quickly, around the house, head and neck raised off the ground cobra-like.

My wife said, “Actually, I think it is a snake.”

“No, it looks like a snake, but it isn’t.” As we spoke, though, it was starting to look more and more snakelike.

“I think it’s an O.A.M.,” she said.

I understood to be an abbreviation for some particular species of mamba. “A mamba. So it’s poisonous. It’s a dangerous snake.”

At this point, two very old people whom I thought of as “mom and dad” (though they didn’t look much like my actual parents or in-laws) came in, and I warned them to be careful of the snake. Ignoring me, and without saying a word, one of them (not sure which) stepped down hard on the snake’s tail, pinning it to the floor. I thought for sure the snake would turn its head back and bite, but instead its whole body straightened out like a rod, its head still up off the ground, its mouth agape in an expression of cartoonish surprise which made me think of a frilled lizard. Then the other member of the old couple stamped down on its head, killing it. The two stamps came in immediate succession — just one-two, and the snake was dead, as if efficient snake-killing were almost a reflex for them. I though to myself, “It seems cruel, but it was necessary. It was a dangerous snake.”


The day after the dream, I went to get some mealworms to feed the gliders, and I noticed that one of the worms — a big one — had escaped from the dish and was crawling around on the floor — rather quickly for a mealworm, I thought, and taking a closer look I saw that it was actually a little black venomous centipede. This was only the second time I’d encountered a centipede in Taiwan, despite having lived here for over six years. The gliders would surely attack it if they found it, their instinct being to jump on anything that looks even remotely wormlike, and a centipede bite could conceivably be fatal to such a small animal. Not wanting to take any chances, I decided to kill the thing. It had crawled under the worm stand by now, so I picked up the stand and moved it, saw the centipede scurrying around, and stepped on it, crushing it. I don’t normally step on pests, preferring to use my hands or a bug zapper, but it was moving fast and I had to get it.


In real life, as in the dream, there was a fast-moving, dangerously venomous, black worm-shaped animal which I at first thought was a worm; I found it near the mealworms; and it was killed by someone stepping on it. Many of the details are different, of course, but would you consider the dream to contain a garbled anticipation of actual events?

I’m guessing that most people would probably say no, that the similarities are too inexact to be worth noticing, that what we have here is perhaps a mildly interesting coincidence but not anything that could reasonably be considered evidence for precognition.

But suppose instead that I told you that the centipede incident had happened the day before the dream, not the day after, and offered it as evidence that dreams sometimes contain garbled memories of recent waking-life events? Would your reaction be any different?

Because that’s what really happened. I described the dream as precognitive as a thought experiment, but in fact I killed the centipede on Monday evening just before going to bed and dreamed about the worm/snake that night. When I woke up and recorded the dream, I took it for granted that of course it had been inspired by the centipede incident. In fact, most of my dreams (the ones I can remember, anyway) contain obvious references to or distortions of recent experiences, books I’ve recently read, etc. If the dream had come first and the centipede incident second, though, I doubt if I would even have noticed any connection.

This is exactly what Dr. Charlton (summarizing Mr. Dunne) describes:

Anticipate that the waking mind will resist associations between a dream and subsequent event – therefore read the dream records with care. Associations between dreams and the past will be obvious and acceptable to the mind as obviously causal; but there is an inbuilt reluctance to recognize associations with the future – to do this is more like a process of pattern recognition, and the experimenter tends to become distracted by stories and meanings. Even apparently trivial or tenuous associations need to be properly followed-up and evaluated.

So perhaps this is a reasonable question to ask yourself when evaluating a possibly precognitive dream: If the sequence were reversed — if the waking events happened first and the dream came after — how confident would you be in concluding that the dream had been influenced by memories of those events?


This post was originally going to end with the previous paragraph, but, after spending so much time thinking and writing about this dream, it occurs to me that, in addition to its obvious connections with the past, it did also contain some hints of future experiences.

On Monday afternoon, the day before the dream, I stopped by a bookstore and picked up Hemingway’s hunting memoir Green Hills of Africa, which I had never read before. I glanced at the back cover in the store but didn’t even open the book until Wednesday. I’m about halfway into it now. The plot so far consists of Hemingway, his wife, and a few friends traipsing around Africa shooting various large animals, occasionally for meat but mostly just for the hell of it. Hemingway and his wife are always called Papa and Mama, respectively, by their hunting companions, and Hemingway himself always refers to his wife as P.O.M. (for “poor old Mama”). This is interesting because of the “mom and dad” in my dream, who were clearly not my actual mom and dad, and who showed up to casually kill a large animal. The use of the abbreviation O.A.M. for the snake also seems to have anticipated my reading about P.O.M. (Actually, the excerpt on the back cover, which I read before the dream, includes a mention of P.O.M., but it gives no indication of who that is or what the letters stand for. In the dream, I didn’t know what O.A. stood for, but I assumed that the M stood for mamba — pretty close to Mama.) There is also a passage early on in Green Hills in which Hemingway vividly describes his fear and hatred of snakes.

None of this, I admit, sounds very impressively precognitive. But I ask myself, if I had read the book before having the dream, would I assume that the one had influenced the other? — and the answer is yes. If I’m going to do this experiment properly, I need to get used to thinking this way.


Filed under Anecdotes, Dreams, Precognition / Prophecy