What is science?

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

Because of my interest in the history and philosophy of science I am sometimes called upon to answer the question “what is science?” Most people think that the answer should be fairly straightforward. This is because science is such an integral part of our lives that everyone feels that they intuitively know what it is and think that the problem of defining science is purely one of finding the right combination of words that captures their intuitive sense.
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Necessary and sufficient conditions

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

The problem of finding definitions for things that clearly specify whether an object belongs in that category or not has long been recognized to be a knotty philosophical problem. Ideally what we would need for a good definition is to have both necessary and sufficient conditions, but it is not easy to do so.

A necessary condition is one that must be met if the object is to be considered even eligible for inclusion in the category. If an object meets this condition, then it is possible that it belongs in the category, but not certain. If it does not meet the condition, then we can definitely say that it does not belong. So necessary conditions for something can only classify objects into “maybe belongs” or “definitely does not belong.”

For example, let us try to define a dog. We might say that a necessary condition for some object to be considered as a possible dog is that it be a mammal. So if we know that something is a mammal, it might be a dog or it might be another kind of mammal, say a cat. But if something is not a mammal, then we know for sure it is not a dog.

A sufficient condition, on the other hand, acts differently. If an object meets the sufficient condition, then it definitely belongs. If it does not meet the sufficient condition, then it may or may not belong. So the sufficient condition can be used to classify things into “definitely belongs” or “maybe belongs.”

So for the dog case, if a dog has papers certified by the American Kennel Association, then we can definitely say it is a dog. But if something does not have such papers it may still be a dog (say a mixed breed) or it may not be a dog (it may be a table).

A satisfactory demarcation criterion would have both necessary and sufficient conditions because only then can we say of any given object that it either definitely belongs or it definitely does not belong. Usually these criteria take the form of a set of individually necessary conditions that, taken together, are sufficient. i.e., Each condition by itself is not sufficient but if all are met they become sufficient.

It is not easy to find such conditions, even for such a seemingly simple category as dogs, and that it the problem. So for the dog, we might try define it by saying that it is a mammal, with four legs, barks, etc. But people who are determined to challenge the criteria could find problems (What exactly defines a mammal? What is the difference between an arm and a leg? What constitutes a bark? Etc. We can end up in an infinite regression of definitions.)

This is why philosophers like to say that we make such identifications (“this is a dog, that is a cat”) based on an intuitive grasp of the idea of “similarity classes,” things that share similarities that may not be rigidly definable. So even a little child can arrive at a pretty good idea of what a dog is without formulating a strict definition, by encountering several dogs and being able to distinguish what separates dog-like qualities from non-dog like qualities. It is not completely fool proof. Once in a while we may come across a strange looking animal, some exotic breed that baffles us. But most times it is clear. We almost never mistake a cat for a dog, even though they share many characteristics, such as being small four-legged mammals with tails that are domestic pets.

Anyway, back to science, a satisfactory demarcation would require that we be able to find both necessary and sufficient criteria that can be used to define science, and use those conditions to separate ideas into science and non-science. Do such criteria exist? To answer that question we need to look at the history of science and see what are the common features that are shared by those bodies of knowledge we confidently call science.

This will be discussed in the next posting.

Improving the quality of our snap judgments

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

In a previous post, I mentioned that my Race IAT results indicated that I had no automatic preference for black or white people. This surprised me, frankly. Although I am intellectually committed to thinking of people as equal, I am still subjected to the same kinds of images and stereotypes as everyone else in society so I expected to have at least a small automatic preference for white people. But the section on Malcolm Gladwell’s book Blink on ‘priming’ experiments might give an explanation for the null result.

The priming experiments were done by psychologist John Bargh. What he did was give two randomly selected groups of undergraduate students a small test involving words. The results of the word test itself were not relevant. What was relevant was that the first set of students encountered words like “aggressively”, “bold, “rude”, “bother”, etc. in their test while the second set encountered words like “respect”, “considerate”, “patiently”, “polite”, etc.

After they had done the word test, the students were asked to go down the hall to the person running the experiment to get their next assignment. This was the real experiment because it had been arranged to have a confederate blocking the doorway, carrying on an inane and seemingly endless conversation with the experimenter. The experiment was designed to see if the set of students who had been unknowingly ‘primed’ with aggressive words would take longer to interrupt this conversation than those who had been primed with polite words. Bargh expected to see a difference, but expected that difference to be measured in milliseconds. He said “I mean, these are New Yorkers. They aren’t going to just stand there. We thought maybe a few seconds, or a minute at most.”

What he found was that the people primed to be rude eventually interrupted after an average of five minutes, but 82% of the people primed to be polite did not interrupt at all, even after ten minutes which was the cut-off time that had been pre-set for the experiment, thinking that no one would ever wait that long.

What these and other priming experiments suggest is that the kinds of experiences we have carry their effects subconsciously over to the next events, at least for some time.

This may explain my negative result because for some time now I have been studying the achievement gap between black and white students in the US. The more I looked at it, the more I became convinced that the concept of race is biologically indefensible, that it cannot be the cause of the gap, and that the reasons for the gap have to be looked for elsewhere.

Since my book on the subject called The Achievement Gap in US Education: Canaries in the Mine came out in June 2005, I had been thinking a lot about these ideas at the same time as I took the test, and so I was probably ‘primed’ to think that there is no fundamental difference between the races, and hence my null result on the Race IAT test.

This ties in with other research that I quote in my book that deals with the role that teacher expectations of students play in student achievement. Teacher expectations are an important factor but a lot of the efforts to improve teacher expectations of low-achieving students have been along the lines “All children can learn!” sloganeering. But having teachers just saying this or plastering it on school walls may not help much, if they are not convinced of its truth. If people are conscious that they are being primed, then the priming effect disappears.

What is needed is for teachers to improve their overall expectations of students is for them to have opportunities to actually see for themselves traditionally underachieving students excelling. If they can have such experiences, then the inevitable snap judgments they make about students, and which can have an effect on student performance, may be more equitable than they are now.

I have long been in favor of diversity in our educational environments but my reasons were more social, because I felt that we all benefit from learning with, and from, those whose backgrounds and experiences differ from our own. But it seems that there is an added bonus as well. When we have a broader base of experience on which to base our judgments, our snap judgments tend to be better.

Snap judgments and prejudices

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

In an earlier post, I described Malcolm Gladwell’s book Blink about the way we instinctively make judgments about people. The way we make snap judgments is by ‘thin-slicing’ events. We take in a small slice of the phenomena we observe and associate the information in those slices with other measures. People who make good snap judgments are those people who associate the thin-slice information with valid predictors of behavior. People who make poor or prejudicial judgments are those people who associate the thin-slice information with poor predictors.

Think about what you observe about a person immediately as that person walks into your view. Gender, ethnicity, height, weight, color, gait, dress, hair, demeanor, eyes, looks, physique, gestures, voice, the list just goes on. We sweep up all these impressions in a flash. And based on them, whether we want to or not, we make a judgment about the person. Different people will weigh different elements in the mix differently.

If someone comes into my office wearing a suit, my initial impression of the person is different than if she had come in wearing jeans. (If you were mildly surprised by my using the pronoun ‘she’ towards the end of the last sentence, it is because, like me, you implicitly associate suits with male attire, so that the first part of the sentence made you conjure up a mental image of a man.)

A personal example of snap judgments occurs when I read Physics Today which I get every month. The obituary notices in have the magazine have a standard form. There is a head-shot of the person, with the name as the header, and one or two column inches describing the person.

Almost all of the obituaries are of old white men, not surprising for physicists of the generation that is now passing away. I found myself looking at the photo and immediately identifying whether the person was of English nationality or not. And I was right a surprising number of times. And I was not reasoning it through in any conscious way. As soon as I saw the picture came into view, I’d find myself thinking “English” or “not English”. I don’t know the basis of my judgments. But as I said, I was right surprisingly often.

Gladwell describes a very successful car salesman who over the years has realized that gender, ethnicity, clothes, etc. are not good predictors of whether the person is likely to buy a car or not. Someone who his fellow salespeople might ignore or dismiss because he looks like a rustic farmer, this salesman takes seriously. And because this salesman has been able to shape his intuition to ignore superficial or irrelevant things, his senses are better attuned to pick up on those cues that really matter.

Some of the strongest associations we make are those based on ethnicity, gender, and age. We immediately associate those qualities with generalizations associated with those groupings.

People are not always comfortable talking about their attitudes on race, gender, and other controversial topics. This is why surveys on such topics are unreliable, because people can ‘psyche out’ the tests, answering in the way they think they are expected to, the ‘correct’ way, rather than what they actually feel. This is why opinion polls on such matters, or in elections where the candidates are of different races or ethnicities, are hard to rely on.

There is a website, developed by researchers at Harvard University, that recognizes this problem. They have designed a survey instrument that tries to overcome this feature by essentially (as far as I can tell) measuring the time taken to answer their questions. In other words, they are measuring the time taken for you to psyche out the test. Since we have much less control over this, the researchers believe that this survey gives a better result. They claim that you cannot change your score by simply taking the test over and over again and becoming familiar with it.

If you want to check it out for yourself, go to the test site, click on “Demonstration”, then on “Go to Demonstration Tests”, then on “I wish to proceed”. This takes you to a list of Implicit Association Tests (or IAT) and you can choose which kinds of associations you wish to check that you make.

I took the Race IAT because that was what was discussed in Gladwell’s book, and it took me less than five minutes to complete. This test looks at the role that race plays in making associations. In particular it looks at whether we instinctively associate black/white people with good/bad qualities.

It turns out that more than 80% of people who have taken this test have pro-white associations, meaning that they tend to associate good qualities with white people and bad qualities with black people. This does not mean that such people are racists. They may well be very opposed to any kind of racist thinking or policies. What these tests are measuring are unconscious associations that we pick up (from the media, the people we know, our community, etc.) without being aware of them, that we have little control over.

Gladwell himself says that the test “always leaves me feeling a bit creepy.” He found himself being rated as having a moderate automatic preference for whites although he labels himself half black because his mother is Jamaican.

I can see why this kind of test is unnerving. It may shake our image of ourselves and reveal to us the presence of prejudices that we wish we did not have. But if we are unconsciously making associations of whatever kind, isn’t it better to know this so that we can take steps to correct for them if necessary? The successful car salesman became so because he realized that people in his profession made a lot of the unconscious associations that were not valid and had to be rejected. And he used that knowledge in ways that benefited him and his customers.

Although you cannot change your Race IAT scores by simply redoing the test, there are other things that can change your score. When I took the Race IAT, the results indicated that I have no automatic preference for blacks or whites. In a later posting, I will talk about the effects that ‘priming’ might have on the test results, and how that might have affected my results.

POST SCRIPT: Saying Iraq and Iran

I noticed that President Bush pronounces Iran the same way that I do (“E-rahn”) but pronounces Iraq as “Eye-rack” (instead of “E-rahk”), which really grates on me. He is not the only one who does this.

I don’t know how the people who live in those two countries pronounce the names but it seems reasonable to me to pronounce the two names similarly except for the last letter. Merriam-Webster’s online dictionary, which provides audio as well, agrees with me on this.

Snap judgments

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

I just finished reading Malcolm Gladwell’s book Blink. It deals with how we all make snap judgments about people and things, sometimes within a couple of seconds or less. Gladwell reports on a whole slew of studies that suggest that we have the ability to ‘thin-slice’ events, to make major conclusions from just a narrow window of observations.

I first read about this as applied to teaching in an essay by Gladwell that appeared in the New Yorker (May 29, 2000) where he described research by psychologists Nalini Ambady and Robert Rosenthal who found that by showing observers silent videoclips of teachers in action, the observers (who had never met the teachers before) were able to make judgments of teacher effectiveness that correlated strongly with the evaluations of students who had taken an entire course with that teacher. (Source: Half a Minute: Predicting Teacher Evaluations From Thin Slices of Nonverbal Behavior and Physical Attractiveness, Journal of Personality and Social Psychology, 1993, vol. 64, No. 3, 431-441.)
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Atheism and Agnosticism

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

In an interview, Douglas Adams, author of The Hitchhiker’s Guide to the Galaxy, who called himself a “radical atheist,” explains why he uses that term (thanks to onegoodmove):

I think I use the term radical rather loosely, just for emphasis. If you describe yourself as “Atheist,” some people will say, “Don’t you mean ‘Agnostic’?” I have to reply that I really do mean Atheist. I really do not believe that there is a god – in fact I am convinced that there is not a god (a subtle difference). I see not a shred of evidence to suggest that there is one. It’s easier to say that I am a radical Atheist, just to signal that I really mean it, have thought about it a great deal, and that it’s an opinion I hold seriously…

People will then often say “But surely it’s better to remain an Agnostic just in case?” This, to me, suggests such a level of silliness and muddle that I usually edge out of the conversation rather than get sucked into it. (If it turns out that I’ve been wrong all along, and there is in fact a god, and if it further turned out that this kind of legalistic, cross-your-fingers-behind-your-back, Clintonian hair-splitting impressed him, then I think I would chose not to worship him anyway.) . . .

And making the move from Agnosticism to Atheism takes, I think, much more commitment to intellectual effort than most people are ready to put in. (italics in original)

I think Adams is exactly right. When I tell people that I am an atheist, they also tend to suggest that surely I must really mean that I am an agnostic. (See here for an earlier discussion of the distinction between the two terms.) After all, how can I be sure that there is no god? In that purely logical sense they are right, of course. You cannot prove a negative so there is always the chance that not only that a god exists but, if you take radical clerics Pat Robertson and Jerry Falwell seriously, has a petty, spiteful, vengeful, and cruel personality.

When I say that I am atheist, I am not making that assertion based on logical or evidentiary proofs of non-existence. It is that I have been convinced that the case for no god is far stronger than the case for god. It is the same reasoning that makes me convinced that quantum mechanics is the theory to use for understanding sub-atomic phenomena or natural selection is the theory to be preferred for understanding the diversity of life. There is always the possibility that these theories are ‘wrong’ in some sense and will be superceded by other theories, but those theories will have to have convincing evidence in their favor.

If, on the other hand, I ask myself what evidence there is for the existence of a god, I come up empty. All I have are the assurances of clergy and assertions in certain books. I have no personal experience of it and there is no scientific evidence for it.

Of course, as long time readers of this blog are aware, I used to be quite religious for most of my life, even an ordained lay preacher of the Methodist Church. How could I have switched? It turns out that my experience is remarkably similar to that of Adams, who describes why he switched from Christianity to atheism.

As a teenager I was a committed Christian. It was in my background. I used to work for the school chapel in fact. Then one day when I was about eighteen I was walking down the street when I heard a street evangelist and, dutifully, stopped to listen. As I listened it began to be borne in on me that he was talking complete nonsense, and that I had better have a bit of a think about it.

I’ve put that a bit glibly. When I say I realized he was talking nonsense, what I mean is this. In the years I’d spent learning History, Physics, Latin, Math, I’d learnt (the hard way) something about standards of argument, standards of proof, standards of logic, etc. In fact we had just been learning how to spot the different types of logical fallacy, and it suddenly became apparent to me that these standards simply didn’t seem to apply in religious matters. In religious education we were asked to listen respectfully to arguments which, if they had been put forward in support of a view of, say, why the Corn Laws came to be abolished when they were, would have been laughed at as silly and childish and – in terms of logic and proof -just plain wrong. Why was this?
. . .
I was already familiar with and (I’m afraid) accepting of, the view that you couldn’t apply the logic of physics to religion, that they were dealing with different types of ‘truth’. (I now think this is baloney, but to continue…) What astonished me, however, was the realization that the arguments in favor of religious ideas were so feeble and silly next to the robust arguments of something as interpretative and opinionated as history. In fact they were embarrassingly childish. They were never subject to the kind of outright challenge which was the normal stock in trade of any other area of intellectual endeavor whatsoever. Why not? Because they wouldn’t stand up to it.
. . .
Sometime around my early thirties I stumbled upon evolutionary biology, particularly in the form of Richard Dawkins’s books The Selfish Gene and then The Blind Watchmaker and suddenly (on, I think the second reading of The Selfish Gene) it all fell into place. It was a concept of such stunning simplicity, but it gave rise, naturally, to all of the infinite and baffling complexity of life. The awe it inspired in me made the awe that people talk about in respect of religious experience seem, frankly, silly beside it. I’d take the awe of understanding over the awe of ignorance any day.

What Adams is describing is the conversion experience that I described earlier when, suddenly switching your perspective seems to make everything fall into place and make sense.

For me, like Adams, I realized that I was applying completely different standards for religious beliefs than I was for every other aspect of my life. And I could not explain why I should do so. Once I jettisoned the need for that kind of distinction, atheism just naturally emerged as the preferred explanation. Belief in a god required much more explaining away of inconvenient facts than not believing in a god.

POST SCRIPT: The Noah’s Ark horror

One of the great triumphs of Judeo-Christian propaganda is getting their followers to overlook the fact that the Biblical Noah story, which many of them believe to be true, would be the worst act of genocide ever, and committed by god to boot. Hellbound Alleee tries to correct this.

Precision in language

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

Some time ago, a commenter to this blog sent me a private email expressing this view:

Have you ever noticed people say “Do you believe in evolution?” just as you would ask “Do you believe in God?” as if both schools of thought have equal footing? I respect others’ religious beliefs as I realize I cannot disprove God just as anyone cannot prove His existence, but given the amount of evidence for evolution, shouldn’t we insist on asking “Do you accept evolution?”

It may just be semantics, but I feel that the latter wording carries an implied affirmation just as “Do you accept that 2+2=4?” carries a different meaning than “Do you believe 2+2=4?”

I guess the point I’m trying to make is that by stating something as a belief, it opens the debate to the possibility that something is untrue. While this may fine for discussions of religion, shouldn’t the scientific community be more insistent that a theory well supported by physical evidence, such as evolution, is not up for debate?

It’s a good point. To be fair, scientists themselves are partly responsible for this confusion because we also say that we “believe” in this or that scientific theory, and one cannot blame the general public from picking up on that terminology. What is important to realize, though, is that the word ‘believe’ is being used by scientists in a different sense from the way it is used in religion.

The late and deeply lamented Douglas Adams, author of The Hitchhiker’s Guide to the Galaxy, who called himself a “radical atheist” puts it nicely (thanks to onegoodmove):

First of all I do not believe-that-there-is-not-a-god. I don’t see what belief has got to do with it. I believe or don’t believe my four-year old daughter when she tells me that she didn’t make that mess on the floor. I believe in justice and fair play (though I don’t know exactly how we achieve them, other than by continually trying against all possible odds of success). I also believe that England should enter the European Monetary Union. I am not remotely enough of an economist to argue the issue vigorously with someone who is, but what little I do know, reinforced with a hefty dollop of gut feeling, strongly suggests to me that it’s the right course. I could very easily turn out to be wrong, and I know that. These seem to me to be legitimate uses for the word believe. As a carapace for the protection of irrational notions from legitimate questions, however, I think that the word has a lot of mischief to answer for. So, I do not believe-that-there-is-no-god. I am, however, convinced that there is no god, which is a totally different stance. . .

There is such a thing as the burden of proof, and in the case of god, as in the case of the composition of the moon, this has shifted radically. God used to be the best explanation we’d got, and we’ve now got vastly better ones. God is no longer an explanation of anything, but has instead become something that would itself need an insurmountable amount of explaining…

Well, in history, even though the understanding of events, of cause and effect, is a matter of interpretation, and even though interpretation is in many ways a matter of opinion, nevertheless those opinions and interpretations are honed to within an inch of their lives in the withering crossfire of argument and counterargument, and those that are still standing are then subjected to a whole new round of challenges of fact and logic from the next generation of historians – and so on. All opinions are not equal. Some are a very great more robust, sophisticated and well supported in logic and argument than others.

When someone says that they believe in god, they mean that they believe something in the absence of, or even counter to, the evidence, and even to reason and logic. When scientists say they believe a particular theory, they mean that they believe that theory because of the evidence and reason and logic, and the more evidence there is, and the better the reasoning behind it, the more strongly they believe it. Scientists use the word ‘belief’ the way Adams says, as a kind of synonym for ‘convinced,’ because we know that no scientific theory can be proven with 100% certainty and so we have to accept things even in the face of this remaining doubt. But the word ‘believe’ definitely does not carry the same meaning in the two contexts.

This can lead to the generation of confusion as warned by the commenter but what can we do about it? One option is, as was suggested, to use different words, with scientists avoiding use of the word ‘believe.’ I would have agreed with this some years ago but I am becoming increasingly doubtful that we can control the way that words are used.

For example, there was a time when I used to be on a crusade against the erroneous use of the word ‘unique’. The Oxford English Dictionary is pretty clear about what this word means:

  • Of which there is only one; one and no other; single, sole, solitary.
  • That is or forms the only one of its kind; having no like or equal; standing alone in comparison with others, freq. by reason of superior excellence; unequalled, unparalleled, unrivalled.
  • Formed or consisting of one or a single thing
  • A thing of which there is only one example, copy, or specimen; esp., in early use, a coin or medal of this class.
  • A thing, fact, or circumstance which by reason of exceptional or special qualities stands alone and is without equal or parallel in its kind.

It means, in short, one of a kind, so something is either unique or it is not. There are no in-betweens. And yet, you often find people saying things like “quite unique” or “very unique” or “almost unique.” I used to try and correct this but have given up. Clearly, people in general think that unique means something like “rare” and I don’t know that we can ever change this even if we all become annoying pedants, correcting people all the time, avoided at parties because of our pursuit of linguistic purity.

Some battles, such as with the word unique are, I believe, lost for good and I expect the OED to add the new meaning of ‘rare’ some time in the near future. It is a pity because then we would then be left with no word with the unique meaning of ‘unique’, but there we are. We would have to say something like ‘absolutely unique’ to convey the meaning once reserved for just ‘unique.’

In science too we often use words with precise operational meanings while the same words are used in everyday language with much looser meanings. For example, in physics the word ‘velocity’ is defined operationally by the situation when you have an object moving along a ruler and, at two points along its motion, you take ruler readings and clock readings, where the clocks are located at the points where the ruler readings are taken, and have been previously synchronized. Then the velocity of the moving object is the number you get when you take the difference between the two ruler readings and divide by the difference between the two clock readings.

Most people (especially sports commentators) have no idea of this precise meaning when they use the word velocity in everyday language, and often use the word synonymously with speed or, even worse, acceleration, although those concepts have different operational meanings. Even students who have taken physics courses find it hard to use the word in its strict operational sense.

Take, for another example, the word ‘theory’. By now, as a result of the intelligent design creationism (IDC) controversy, everyone should be aware that the way this word is used by scientists is quite different from its everyday use. In science, a theory is a powerful explanatory construct. Science depends crucially on its theories because they are the things that give it is predictive power. “There is nothing so practical as a good theory” as Kurt Lewin famously said. But in everyday language, the word theory is used as meaning ‘not factual,’ something that can be false or ignored.

I don’t think that we can solve this problem by putting constraints on how words can be used. English is a wonderful language precisely because it grows and evolves and trying to fix the meanings of words too rigidly would perhaps be stultifying. I now think that we need to change our tactics.

I think that once the meanings of words enter mainstream consciousness we will not be successful in trying to restrict their meanings beyond their generally accepted usage. What we can do is to make people aware that all words have varying meanings depending on the context, and that scientific and other academic contexts tend to require very precise meanings in order to minimize ambiguity.

Heidi Cool has a nice entry where she talks about the importance of being aware of when you are using specialized vocabulary, and the need to know your audience when speaking or writing, so that some of the pitfalls arising from the imprecise use of words can be avoided.

We have to realize though that despite our best efforts, we can never be sure that the meaning that we intend to convey by our words is the same as the meaning constructed in the minds of the reader or listener. Words always contain an inherent ambiguity that allows the ideas expressed by them to be interpreted differently.

I used to be surprised when people read the stuff I wrote and got a different meaning than I had intended. No longer. I now realize that there is always some residual ambiguity in words that cannot be overcome. While we can and should strive for maximum precision, we can never be totally unambiguous.

I agree with philosopher Karl Popper when he said, “It is impossible to speak in such a way that you cannot be misunderstood.” The best we can hope for is to have some sort or negotiated consensus on the meanings of ideas.

POST SCRIPT: Huckabee and Paul

Alexander Cockburn discusses why Mike Huckabee and Ron Paul are the two most interesting candidates on the Republican side.

Atheism and meaning

(As is my custom this time of year, I am taking some time off from writing new posts and instead reposting some old favorites (often edited and updated) for the benefit of those who missed them the first time around or have forgotten them. The POST SCRIPTS will generally be new. New posts will start again on Monday, January 5, 2009. Today’s post originally appeared in October 2007.)

People often think that atheists do not have a life affirming philosophy. They have sometimes taken the quote by prominent atheist Richard Dawkins (Scientific American November 1995, p. 85) that “The universe that we observe has precisely the properties we should expect if there is, at bottom, no design, no purpose, no evil, no good, nothing but pitiless indifference” to argue that atheism leads to a philosophy of hopelessness and despair. I have heard several talks by intelligent design creationism advocate Michael Behe and he repeatedly uses the quote to get a laugh at the expense of atheism by saying that Dawkins must be a real downer at parties. But anyone who has seen interviews with Dawkins and read his writings will come away with the contrary impression, that he is a witty, courteous, and engaging man with a mischievous sense of humor. One can well imagine him livening up any party. Dawkins was merely making a factual observation about the nature of the universe, saying that it is futile to try and obtain our meaning and purpose externally from the universe, although we can observe it with awe and wonder. We can, and should, construct meaning and purpose for our lives.
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Opinion polls and statistics

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

As the 2008 election season gets into high gear, we will get inundated with the results of opinion polls. Many of our public policies are strongly influenced by these polls, with politicians paying close attention to them before speaking out.

But while people are inundated with opinion polls, there is still considerable misunderstanding about how they work. Especially during elections, when there are polls practically every day, one often hears people expressing skepticism about polls, saying that they feel the polls are not representative because they, personally, and all the people they know, have never been asked their opinion. Surely, they reason, if so many polls are done, every person should get a shot at answering these surveys? That fact that no pollster has contacted them or their friends and families seem to make the poll results suspect in their eyes, as if the pollsters are using some highly selective group of people to ask and leaving out ‘ordinary’ people.

This betrays a misunderstanding of statistics and the sampling size needed to get good results. The so-called “margin of error” quoted by statisticians is found by dividing 100 by the square root of the size of the sample. So if you have a sample of 100, then the margin of error is 10%. If you have a sample size of 625, then the margin of error drops sharply to 4%. If you have a sample size of 1111, the margin of error becomes 3%. To get to 2% requires a sample size of 2500.

Clearly you would like your margin of error to be as small as possible, which argues for large samples, but your sample sizes are limited by the cost and time involved in surveying people, so trade offs have to be made. Most pollsters use samples of about 1000, and quote margins of error of 3%.

One interesting point is that there are statistical theorems that say that the sample size needed to get a certain margin of error does not depend on the size of the whole population (for large enough populations, say over 100,000). So a sample size of 1000 is sufficient for Cuyahoga County, the state of Ohio, or the whole USA. This explains why any given individual is highly unlikely to be polled. Since the population of the US is close to 300 million, any one of the 1000 people I may personally know has only a 0.00033% probability of being contacted.

We know that a poll tells us that 54% of Americans say that “I do not think human beings developed from earlier species.” The sample size was 1000, which means a margin of error of about 3%. Statistically, this means that there is a 95% chance that the “true” percentage of people who agree with that statement (i.e., the number we would get if could actually ask each and every person on the country) lies somewhere between 51% and 57%.

Certain assumptions and precautions go into interpreting these results. The first assumption is that the people polled are a truly random sample of the population. If you randomly contact people, that may not be true. You may, for example, end up with more women than men, or you may have contacted more old people or registered Republicans than are in the general population. If, from census and other data, you know the correct proportions of the various subpopulations in your survey, then this kind of skewing can be adjusted for by changing the weight of the contributions from each subgroup to match the actual population distribution.

With political polls, sometimes people complain that the sample sizes of Democrats and Republicans are not equal and that thus the poll is biased. But that difference is usually because the number of people who are officially registered as belonging to those parties are not equal.

But sometimes pollsters also quote the results for the subpopulations in their samples, and since the subsamples are smaller, the breakdown data has greater margin of error than the results for the full sample, though you are often not explicitly told this. For example, the above-mentioned survey says that 59% of people who had high school education or less agreed that “I do not think human beings developed from earlier species.” But the number of people in the sample who fit that description is 407, which means that there is a 5% uncertainty in the result for that subgroup, unlike the 3% for the full sample of 1000.

But a more serious source of uncertainty these days is that many people refuse to answer pollsters when they call and it is not possible to adjust for the views of those who refuse. So although the pollsters do have data on the numbers of persons who hang up on them or otherwise refuse to answer, they do not know if such people are more likely or less likely to think that humans developed from earlier species. So they cannot adjust for this factor. They have to simply assume that if those non-responders had answered, their responses would have been in line with those who actually did respond.

Then there may be people who do not answer honestly for whatever reason or are just playing the fool. They are also hard to adjust for. This is why I am somewhat more skeptical of surveys of teens on various topics. It seems to me that teenagers are just the right age to get enjoyment from deliberately answering questions in exotic ways.

These kinds of biases are hard, if not impossible, to compensate for, though in serious research the researchers try to put in extra questions that can help gauge whether people are answering honestly. But opinion polls, which have to be done quickly and cheaply, are not likely to go to all that trouble

Because of such reasons, polls like the Harris poll issue this disclaimer at the end:

In theory, with probability samples of this size, one could say with 95 percent certainty that the overall results have a sampling error of plus or minus 3 percentage points of what they would be if the entire U.S. adult population had been polled with complete accuracy. Sampling error for subsamples is higher and varies. Unfortunately, there are several other possible sources of error in all polls or surveys that are probably more serious than theoretical calculations of sampling error. They include refusals to be interviewed (nonresponse), question wording and question order, and weighting. It is impossible to quantify the errors that may result from these factors.

For all these reasons, one should take the quoted margins of error, which are based purely on sample size, with a considerable amount of salt.

There is one last point I want to make concerning a popular misconception propagated by news reporters during elections. If an opinion poll says that a sample of 1000 voters has candidate A with 51% support and candidate B with 49%, then since the margin of error (3%) is greater than the percentage of votes separating the candidates (2%), the reporters will often say that the race is a “statistical dead heat,” implying that the two candidates have equal chances of winning.

Actually, this is not true. What those numbers imply (using math that I won’t give here) is that there is about a 75% chance that candidate A truly does lead candidate B, while candidate B has only a 25% chance of being ahead. So when one candidate is three times as likely as the other to win, it is highly misleading to say that the race is a “dead heat.”

POST SCRIPT: Inflated value of religion

Many people have an inflated sense of the value of religion that simply falls apart on close examination. For example, Mike Huckabee said the following: “The Ten Commandments form the basis of most of our laws and therefore, you know if you look through them does anybody find anything there that would be all that objectionable? I don’t think most people would if they actually read them.”

He says this as if it is obviously true. But Ed Brayton shows how absurd this is.

The joy of free thinking

(I am taking a break from original posts due to the holidays and because of travel after that. Until I return, here are some old posts, updated and edited, for those who might have missed them the first time around. New posts should appear starting Monday, January 14, 2008.)

There is scarcely a week that does not pass without some interesting new scientific discovery about the nature of life. You open the newspaper and read of observations of light emitted by distant stars from the very edges of the known universe, light that must have been emitted almost at the very beginning, over ten billion years ago. Such research puts us in touch with our own cosmic beginnings.

Just recently there was the discovery of the fossils a possible new Hobbit-like people who lived in a remote island in the Indonesian archipelago about 18,000 years ago. Then there was the discovery in China of an almost perfectly preserved bowl of noodles that is about the 4,000 years old. Discoveries like these shed light on how evolution works and how human society evolved. And then the discovery of Tiktaalik, the 375-million year-old fossil that seems like an intermediary between sea and land animals.

Similarly, the discoveries that come from studies of DNA tell us a lot about where humans probably originated, how we are all related to one another and how, despite our common origins, the species spread over the Earth and diversified. The fact (according to the September 21, 2005 issue of The Washington Post) that we share nearly 99 percent of our DNA with chimpanzees, lend further strong support (not that it needed it) to the evolutionary idea that chimpanzees and humans share a common ancestry. (The approximately one percent difference, according to The Daily Show, is what causes human beings to kill each other!)

I enjoy reading things like this because it reminds me of Charles Darwin’s central idea, that we are all linked together in one great biological evolutionary tree, with the various animal species being our cousins, and even seemingly insignificant things like worms and bacteria having common ancestors with us, however distantly in the past that might have happened. Some people may find the idea of being related to a monkey repulsive but I think it is fascinating. The ability of science to investigate, to find new relationships, to explore and conjecture and come up with answers to old questions as well as create new questions to investigate is one of its greatest qualities.

And for me, personally, being an atheist makes that joy completely unalloyed. Shafars (i.e., secularists, humanists, atheists, freethinkers, agnostics, and rationalists), as well as religious people who interpret their religious texts metaphorically and not literally, do not have any concerns when new headlines describing a new scientific discovery are reported in the news. They do not have to worry whether any new fact will contradict a deeply held religious belief. They do not have to worry about whether they need to reconcile the new information with any unchanging religious text.

On the other hand, the same news items that give us fascinating glimpses of scientific discoveries undoubtedly create fresh headaches for all religious people, and especially those whose beliefs are based on literal readings of religious texts, because each new discovery has to be explained away if it disagrees with some dogma. There are people who devote their entire lives to this kind of apologetics, to ensure that their religious beliefs are made compatible with science. The website Answers in Genesis, for example, is devoted to making Young-Earth creationism (YEC) credible. So it goes to great lengths to show that the earth is less that 10,000 years old, all the animals could have fitted into Noah’s Ark, and that dinosaurs lived at the same time as humans.

One has to admire the tenacity of such people, their willingness to devote enormous amounts of time, sometimes their whole lives, to find support for a belief structure that is continuously under siege from new scientific discoveries. It must feel like trying to hold back the tide. (See this site which heroically tries to fit into a 10,000 year old universe model the astrophysical data received from light emitted by stars that are billions of light years away.)

Of course, scientific discoveries come too thick and fast for even the most determined religious apologists to keep up. So they tend to focus only on explaining away a few questions, the kinds of questions that the lay public is likely to be most concerned about, such as whether dinosaurs existed concurrently with humans, the ages of the universe and the Earth, whether the size of the Ark was sufficient to accommodate all the species, how Noah coped with the logistical problems of feeding all the animals and disposing of the waste, how Adam and Eve’s children could multiply without there already being other people around or indulging in incest, and so on.

But the rest of us don’t have to worry about any of that stuff and so can enjoy new scientific discoveries without any cares, and follow them wherever they lead. It is nice to know that one can throw wide open the windows of knowledge and let anything blow in, clearing out the cobwebs of old ideas and freshening up the recesses of the mind.

It is a wonderful and exhilarating feeling.

So for this new year, I wish all the readers of this blog the joys of free thinking. May your thoughts not be hobbled by superstitions ancient or modern.

POST SCRIPT: The 50 Most Loathsome People in America

I usually avoid reading all the lists of best, worst, etc. that come out this time of year, but this one is actually very good.

Here’s #29 on the list Dinesh D’Souza:

Charges: Wrote a book blaming 9/11 on — who else? — liberals, because if we didn’t live in a free society, then fundamentalists wouldn’t dislike us so. Even conservative nuts blasted D’Souza’s empathy for poor al Qaeda. Lately, he’s been engaging prominent atheists in debates, revealing himself to be a pseudointellectual ass, and then declaring victory. D’Souza’s master plan for attacking atheism is the ridiculous Pascal’s wager: Atheists could be wrong, and then they’d go to hell, but if the religious are wrong, then they suffer no ill effect — aside from living their lives in delusion, of course. And possibly going to someone else’s hell for believing the wrong religion. D’Souza seems to think that if he speaks more loudly and rapidly than his opponent, he is winning, but his arguments are weak and idiotic, and he never even attempts to truly debate the existence of any god, which is the ostensible point of these debates. Instead, he likes to compare body counts — Stalin and Mao killed more than the religious leaders of their time — rather than actually debate whether there is a God, or for that matter a Jesus. This, of course, is because there is no case to be made.

Exhibit A: “[Atheists] are God-haters… I don’t believe in unicorns, but then I haven’t written any books called The End of Unicorns, Unicorns are Not Great, or The Unicorn Delusion.” But what if everyone you met did believe in unicorns, and not only that, but worshiped a unicorn, held a book about unicorns to be the divine truth of the universe, invoked unicorns in political contexts, and speechified about how non-believers were indecent people waging a war on morality, which could only be predicated on the unquestioning belief in unicorns? Then, maybe, D’Souza would think about writing that book. But of course, that’s not really true, because if that was the world we lived in, then Dinesh D’Souza would believe in unicorns.

Sentence: Spanish inquisition.