26 April 2010


Two more arguments for learning statistics

One of my repeated themes here over the years is how genuinely lousy the human brain is at intuitively understanding probability and statistics. Two articles this week had me thinking about it again.

The first was Clive Thompson's latest opinion piece in Wired, "Why We Should Learn the Language of Data," where he argues for significantly more education about stats and probability in school, and in general, because:

If you don't understand statistics, you don't know what's going on—and you can't tell when you're being lied to.

Climate change? The changing state of the economy? Vaccination? Political polls? Gambling? Disease? Making decisions about any of them requires some understanding of how likelihoods and big groups of numbers interact in the world. "Statistics," Thompson writes, "is the new grammar."

The second article explains a key example. At the NPR Planet Money blog (incidentally, the Planet Money podcast is endlessly fascinating, the only one clever enough to get me interested in listening to business stories several times a week), Jacob Goldstein describes why people place bad bets on horse races.

After exhaustive statistical analyses (alas, this stuff isn't easy), economists Erik Snowberg and Justin Wolfers have figured out that even regular bettors at the track simply misperceive how bad their bets are, especially when wagering on long shots—those outcomes that are particularly unlikely, but pay off big if you win, because:

...people overestimate the probability of very rare events. "We're dreadful at perceiving the difference between a tiny probability and a small probability."

In our heads, extremely unlikely things (being in a commercial jet crash, for instance) seem just as probable, or even more probable, than simply somewhat unlikely things (being in a car crash on the way to the airport). That has us make funny decisions. For instance, on occasion couples (parents of young children, perhaps) choose to fly on separate planes so that, in the rare event that a plane crashes, one of them survives. But they both take the same car to the airport—as well as during much of the rest of their lives—which is far, far more likely to kill them both. (Though still not all that likely.)

Unfortunately, so much of probability is counterintuitive that I'm not sure how well we can educate ourselves about it for regular day-to-day decision-making. Even bringing along our iPhones, I don't think we should be using them to make statistical calculations before every outing or every meal. Besides, we could be so distracted by the little screens that we step out into traffic without noticing.

Our minds are required be good at filtering out irrelevancies, so we're not overwhelmed by everything going on around us. But the modern world has changed what's relevant, both to our daily lives and to our long-term interests. The same big brains that helped us make it that way now oblige us to think more carefully about what we do, and why we do it.

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11 June 2009


Going beyond common sense

A few months ago, I posted two quotes about how science works, and why it's effective:

The first principle is that you must not fool yourself—and you are the easiest person to fool. - Richard Feynman

If common sense were a reliable guide, we wouldn't need science in the first place. - Amanda Gefter

Feynman and Gefter sum up what makes science different from many other intellectual pursuits, and why it has so radically changed the human experience over the past few hundred years. Not fooling ourselves turns out to be surprisingly difficult. That's because (to dig up another thing I write about frequently here) our brains aren't built to find the truth. Often, we have to work against our own thinking to do that.

We evolved to get by and reproduce as hunter-gatherer primates on the savannah of Africa, not to follow two or more independent lines of evidence to confirm how fast the universe is expanding. Yet we have figured that out, because scientific thinking is designed to counteract our tendencies to fool ourselves. Sometimes we still do, for awhile, but science also tends to be self-correcting, because it tries to force reality to trump belief.

There's an excellent article in the current issue of the academic journal Evolution: Education and Outreach, titled "Understanding Natural Selection: Essential Concepts and Common Misconceptions" (via PZ Myers). Yes, it's academic and thus (for a web page) pretty long, but there's lots of meat there, and it's written for a general audience. It's worth reading through.

The first part summarizes how natural selection works. The second part asks "why is natural selection so difficult to understand?" After all, it is elegant and logical, and has mountains (literally, in some cases) of evidence behind it, collected and analyzed and correlated and compared and verified over 150 years. However:

Much of the human experience involves overcoming obstacles, achieving goals, and fulfilling needs. Not surprisingly, human psychology includes a powerful bias toward thoughts about the "purpose" or "function" of objects and behaviors [...] the "human function compunction." This bias is particularly strong in children, who are apt to see most of the world in terms of purpose; for example, even suggesting that "rocks are pointy to keep animals from sitting on them".

In other words, one reason it's hard to understand natural selection (or quantum mechanics, or the weather, or geological time) is that we're predisposed to believe that the whole universe is like us.

Indeed, that's often not a bad place to start. Seeing that populations of organisms change over time, early evolutionary theorists proposed that the organisms changed, in effect, because they wanted to, and passed those desired changes on to their offspring. But those ideas had to be discarded when the evidence didn't support them. Similarly, long tradition indicates that many alternative medical therapies might be worth examining, but research shows that most of them don't work.

Intuition and common sense are a good way to find your way through day-to-day life, but they're not especially reliable when trying to figure out how reality works, and thus how to do things that are genuinely new.

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30 May 2009


Luck and randomness

Randomness works in strange ways, at least as far as our minds are concerned. The stars in the sky are distributed essentially randomly (from our viewpoint), yet we see patterns in them—that's because a random distribution is clumpy, not even.

Since our brains seek patterns, we tend to see patterns in random things, like clouds, stains, or the browned surfaces on pieces of toast.

Now check this out: New Jersey grandmother Patricia Demauro played craps at a casino, and rolled a pair of dice 154 times without ever rolling a seven, over the course of more than four hours. The odds? 1.56 trillion to one against. But it happened.

It wasn't impossible, just supremely improbable. Yup, that's random.

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26 May 2009


An extroverted introvert

PhotoFunia - Derek retailPeople are supposed to be either introverted or extroverted, but I've never been sure where I fit. Perhaps I'm an ambivert (yuck, an ugly word):

  • Most of the time, I like meeting new people; I have stage love instead of stage fright (hence why I've taught courses, given speeches and been in a band for so long); I'm decent with small talk at a party or in a crowd; and I can be quite a chatterbox—not to mention loud—in the right context.

  • On the other hand, I always enjoyed being an only child; when I'm uncomfortable or in pain I tend to become quiet and withdrawn; I despise making unsolicited phone calls and am not fond of telephone conversation in general; when out and about (either in my own city or somewhere else) I'm far more likely to wander about alone, take pictures, and think to myself than to strike up conversations with strangers; and I need significant time alone every day, time I often take when the rest of my family is asleep.

So I found Sophia Dembling's "Confessions of an Introverted Traveler" (via Kottke) fascinating. I like her thesis:

Though I don’t need to talk to a lot of people, I love watching them. [...] I travel for the travel.

I suspect I may be primarily an introvert—like Dembling, I find the North American preference for extroversion a bit oppressive. That doesn't mean I prefer solitude in all circumstances, but that social interactions take energy for me, and I need time alone to recharge. I like activities with friends, and especially with my wife and children, but given time to myself, I'm unlikely to want to meet anyone for lunch or a night out. Instead, I might go out by myself, and it doesn't feel at all lonely.

I recall last year's Gnomedex conference in Seattle, an intense three-day geekfest of ideas and discussion together with hundreds of my peers in a Seattle meeting room. The hotel my wife and I chose was a good 20-minute walk away up the waterfront escarpment and through downtown. Despite the physical difficulty of making the trek with my rolling bag of computer and camera gear while suffering cancer-treatment side effects (as I still do), I enjoyed the trip each day. That's because I could be alone and enjoy people-watching as I trundled through the glass tower canyons and Pike Place Market, and either charge up on the way to the meeting, or get my energy back on the way to the hotel.

Right now is a good example too. I've had a rough couple of nights of side effects this week, and my wife is out for the afternoon, but now that I'm finally feeling good, rather than setting up a lunch meeting, or saying hi to my parents (who live next door), I'll probably just go for a solitary walk. That's just what I need.

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19 December 2008


Violence and sex

When you think about it a little, the two major things we prevent our children from seeing, sex and violence, are pretty weird. Not in themselves individually, but on how we fixate on them as a yin-yang pair. What's even weirder is that we treat sex (which, of the two, is certainly the good one) as the worst—even for adults.

Consider: When the great photographic website The Big Picture has a year-end picture retrospective, it warns us about violent images but still lets us see them, but doesn't include any sexual pictures at all, even though I'm sure 2008 included some amazing ones. And your local video rental store puts the porn in a hidden back room, but leaves the horror movies out on the public shelves.

I think I know why.

What I mean is, while we generally protect our kids from seeing extreme violence and gore, whether real or simulated, they still get exposed to a lot of lower-level stuff. Even for rather young children, everything from Mario pounding enemy characters with a hammer in videogames, to Bugs Bunny and Batman cartoons, to TV shows like Destroyed in Seconds (a guilty pleasure both for me and for my ten-year-old daughter) is fair game. As they get older, we're pretty much fine with letting them play more graphic games, watch CSI and Indiana Jones, and see shows where stuff (and people) get blowed up real good.

But apparently we're not going to let them see any sex. Nudity and sexuality are going to get a PG-13 or R or NC-17 from the ratings board a lot more easily than violence. And when was the last time a violent movie received an X rating? Surely any suggestion of sexuality between kids' videogame or TV characters would probably lead to a recall or cancellation—yet it's fine if they punch each other. The key example here? The infamous "hot coffee mod."

Here's my theory. For most people in developed western societies, any violence beyond accidents or schoolyard fisticuffs is pure fantasy. Unless you're a solider or maybe a gang member, or just perhaps a police officer in an extreme and unusual situation, chances are you will never kill or maim anyone on purpose in your entire life. You will never break someone's neck in hand-to-hand combat. You will never blow up a building or shoot down a plane. You will never aim a machine gun or a rocket launcher, or wield a sword in anger. You absolutely will not ever vaporize a planet.

And that's a good thing.

But nearly everyone, once they become adults, eventually has sex. Maybe a lot of it.

And that's also a good thing, or should be.

Children who see violence, especially exaggerated violence of the Donkey Kong or blowed-up-real-good variety, are seeing something they can fantasize about, but which they will never do. Children who see sex are seeing something they will almost certainly do eventually.

And that's why we adults think of sex as more dangerous for our kids. It's why we shield them from it for longer. It's why when we do discuss it at first, we have Serious Talks about the Human Reproductive System. And why we don't have Serious Talks about High Explosives.

Because sex is real, and important, and as we become adolescents we're wired by evolution to want it way more than we want to blow stuff up. So children need to learn about sex as a real thing, so they can make wise decisions when they get there. (How many of us, conversely, ever need to make any sort of decision about, say, wearing ear protection when firing a mortar in battle?)

I'm sure some sociologist has considered this already. However much the dichotomy between sex and violence makes sense, however, it's still pretty weird.

Don't even get me started on swearing.

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12 December 2007


Book Review: Why Beautiful People Have More Daughters

49ERS cHEER at Flickr.comWhen I read Why Beautiful People Have More Daughters (buy at Amazon Canada or Amazon U.S.), I wasn't angry, but I was uncomfortable—and not because one of the authors of this brand-new volume has been dead for almost five years. The book is a summary of the new field of evolutionary psychology, which shows that our evolutionary past strongly influences how humans think and behave today.

UPDATE March 2008: It looks like the main author if this book, Satoshi Kanazawa, is a bit of a wingnut, and also may not be analyzing many of his statistics correctly. I stand by my review of the book here, but my reservations listed in it (especially that there is very little information about what many of the mechanisms of evolutionary psychology are) have become stronger with new evidence. Overall, I'm likely to look at his work more skeptically from now on.

You can see why that might be discomfiting: most of us like to think that we're independent actors, making decisions based on thought, and maybe influenced by our upbringing and our environment. Sometimes we are. But Alan S. Miller (the dead one, who got the project started) and Satoshi Kanazawa (the living one, who finished it) show how often we're not. If you're a creationist or think that all evil derives from patriarchal traditions and corporate media, this book will bug the hell out of you.

Publisher Peguin sent me the book to review at the suggestion of Darren Barefoot. Although my biology degree is a couple of decades old now, I find nothing in the fundamental premises of evolutionary psychology shocking. It only makes sense that, like those of all other animals (more so, since we depend so much on it), our human brain has evolved along with the rest of our body, adapting through natural selection to our environment.

Or, as Miller and Kanazawa point out, to what used to be our environment. We behave, make decisions, and organize ourselves the way we do today largely because it helped our ancestors survive and reproduce in Africa tens of thousands of years ago.

That's where things get interesting, and where the discomfort and controversy arise. Take this, from page 95:

Of course, diamonds and flowers are beautiful, but they are beautiful precisely because they are expensive and lack intrinsic value, which is why it is mostly women who think that diamonds and flowers are beautiful. Their beauty lies in their inherent uselessness; this is why Volvos and potatoes are not beautiful.

A major foundation of evolutionary psychology is that sex drives everything. Or, more accurately, that the differences between how men's and women's genes propagate to our descendants drives much of our behaviour, from the obvious (mating rituals) to the puzzling (wars, jobs, when we choose to travel, what we like to buy). We're just like dogs bred to be aggressive or good at herding sheep, or like birds and fish adapted to flocking and schooling, or predators that survive because natural selection molded their brains to know how to stalk and pounce and kill.

The result is many provocative statements about human beings:

  • Divorced parents with children are playing a game of chicken, and it is usually the mother who swerves.
  • Men do everything they do in order to get laid.
  • Any reasonably attractive young woman exercises as much power as does the (male) ruler of the world.
  • Clear evidence of women's promiscuity [...] is the size and shape of men's genitals and what men do with them.
  • We believe in God for the same reason that men constantly think that women are coming on to them.
  • It is the wife's age, not the husband's, that prompts [a man's] "midlife crisis."
  • Religion is not an adaptation in itself but a byproduct of other adaptations. [...] The human brain [...] is biased to perceive intentional forces behind a wide range of natural physical phenomena [and thus] to see the hand of God at work.
  • Humans are [...] born racist and ethnocentric, and learn through socialization and education not to act on such innate tendencies.
  • Sometimes [a woman saying] "no" [to sex] really does mean "try a little harder."

Why Beautiful People Have More Daughters makes a reasonable case, with lots of reputable research backing it up, that much of the conventional wisdom of psychology and sociology is wrong. The authors and their evolutionary psychologist colleagues argue that many of the improper, cruel, unfair, and evil things (or, for that matter, altruistic, pleasant, equitable, and good things) that people do are not the result of childhood environments, cultural traditions, or power structures.

Rather, our behaviours today—whether our current ethics and morals judge them good or bad—are the same behaviours that helped our ancestors' genes propagate, and thus are the reason we're here now.

Men killing their wives, other men, and their stepchildren. Women wanting, and men liking, long lustrous blonde hair. Religiously motivated suicide bombers being almost exclusively young male Muslims. People of both sexes preferring blue eyes to brown. Women choosing older and more powerful men as mates, but more attractive men as lovers. Essentially all human societies permitting either polygyny (men with multiple wives or mistresses) or serial polygyny (men who marry, divorce, and remarry, usually to younger women). Young single women often traveling abroad to experience the world while their male cohorts tend to stay home and hate foreigners. All have explanations in evolutionary psychology, some more solid than others.

The writing in the book is sometimes a bit manic, as if the authors were yanking me as a reader from example to example, saying, "Look! Look! We're right again!" Some of their conclusions come with lots of convincing scientific evidence, not to mention theoretical predictions about human behaviour that turn out to be true. But others are apparently pure speculation. I also think many of their explanations would have been clearer using the past tense, rather than the present, to keep the role of our ancestral environment clear.

They do show that beautiful people tend to have more daughters, and why that makes sense, but the physiological mechanism of how it happens wasn't clear to me. And neither the authors nor their editors seem to know what "begs the question" is actually supposed to mean.

To be fair, Miller and Kanazawa take pains to note that many of the things we do make little sense in the modern world (meaning the fast-changing one we've been in for the past 10,000 years or so, since the invention of agriculture). But because those behaviours evolved over hundreds of thousands or millions of years before that, we can't help ourselves. And the authors also highlight some areas—homosexuality, declining birthrates in industrialized countries, the willingness to become a soldier—that their field can't explain very well.

We still love sweet and fatty foods, which were once rare and precious but are now overabundant and giving us health problems. Similarly, we behave in ways that begat us more children when living in small groups of hunter-gatherers in a sub-tropical savannah, but which may not be of similar benefit in a world of fast cars, 80-year lifespans, high explosives, supermarkets, birth control, jet travel, antibiotics, and Internet dating.

What made me uncomfortable about the book is that, as a bleeding-heart leftie, of course I want to believe that we are not so driven and constrained by our evolutionary history. But I'm also trained in biology and—even more after reading Miller and Kanazawa—it's clear to me that, like other animals, we must be.

But what we do is not always what we ought to do: Why Beautiful People Have More Daughters reinforces repeatedly that facts (what is) do not determine morals (what should be). As a parallel, knowing that fleas spread bubonic plague doesn't make the plague desirable, and knowing that is key to combating the disease. But, conversely, the way we think things should be isn't necessarily the way they are either. Wanting human nature to compel us to treat each other fairly and well doesn't make that true. We have to find different reasons to make it happen, to overcome much of what is innate in us.

That is yet another lesson of the modern world that my brain, prehistoric as it is, has trouble handling.

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11 November 2007


The Nerd Handbook

I'm pretty nerdy, but not completely so, according to the Nerd Handbook (via Gruber). For instance:

  • I do not see the world as "a system which, given enough time and effort, is completely knowable." We humans can learn a lot, but not everything, which I think is kind of cool.
  • While I have built myself a Cave (in the basement, natch), I don't spend very much time in it since I bought a laptop.
  • I don't love video games. Fun, sure, but I can take them or leave them. It's why we own a Wii instead of an Xbox or PS3.
  • I'm decent at small talk, and I love talking in front of crowds. But I'm not a big fan of calling up strangers on the phone.

However, much of the rest is pretty darn accurate. And going through the article to nit-pick out the parts that don't apply to me is pretty darn nerdy of me too, isn't it?

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22 October 2007


What's the metaphor?

Christmas 2006 crowd at the Austin Airport at Flickr.comI've been having unusual, interesting dreams this week. All of them have been about transportation problems.

Last night it was a strange chase by a Customs agent/bounty hunter who followed my companions and me across the border from the U.S. into Canada. The night before, I was running around an airport, late for a plane, with stuff spilling out of my luggage (by the way, earlier that day, in real life, I'd taken my parents to their flight). A day before that, I was struggling to get aboard a ferry. And Thursday night I was in a crowded van crawling through huge crowds on a muggy street, maybe in New Orleans.

I'm sure this all has something to do with fighting cancer—a way for my brain to try to resolve the frustrations of surgeries and radiation and chemotherapy going on and on and on. Anyone have further analysis?

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30 May 2007


Rejecting reality and believing falsehood

One of my recurring themes here recently has been the ways our Old World primate brains make it difficult for us humans to understand many basic things, including probability and risk, geological time, contingency, extremly large- or small-scale events, and so forth.

Here's another one, an excellent psychology article about why we resist some scientific ideas more than others (via Pharyngula). Coincidentally, Harvard history of science professor Steven Shapin addresses a similar topic on the CBC Ideas podcast this week called "Testing Science" (MP3 file). Essentially, research shows that...

...even one year-olds possess a rich understanding of both the physical world (a "naive physics") and the social world (a "naive psychology"). [...] These intuitions give children a head start when it comes to understanding and learning about objects and people. But these intuitions also sometimes clash with scientific discoveries about the nature of the world, making certain scientific facts difficult to learn.

However, some concepts don't work that way, even when they are far from obvious. For example:

[The existence of germs and electricity] is generally assumed in day-to-day conversation and is not marked as uncertain; nobody says that they "believe in electricity." Hence even children and adults with little scientific background believe that these invisible entities really exist.

That's interesting, because our evidence for those things is pretty indirect, however pervasive: light switches and televisions and computers work, and washing your hands helps prevent infection. But most people have never seen a germ, never mind an electron. It would seem, purely objectively, that being able to look at rock strata in a highway cut, or watch the patterns of a coin flipped over and over, or observe the similarities and differences between chimpanzees and humans at the zoo, or hummingbirds and dragonflies in the garden, would make concepts like deep time and randomness and biological evolution easier to understand than electricity or germ theory.

Yet they are not. Our brains are remarkable things, and one of the most remarkable things about them is that we can, if we work at it as we grow up and throughout our lives, help ourselves get around our own cognitive limitations.

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19 May 2007


Feeling safe vs. being safe

Via netdud, I read once again another highly sensible article from Bruce Schneier about how badly we as a society usually react to security threats. It's a strange contrast to, and yet also a perfect demonstration of, my post yesterday about the Air India bombing, where it seems that direct, credible, likely threats didn't receive the attention they deserved—while today we confiscate nail clippers and remove shoes at airport security in a way that is likely totally ineffective.

I've written repeatedly about this stuff over the years here on my blog: about how our African savannah brains are poorly equipped to deal with the risks we face in the modern world.

But in another essay, Schneier also makes the point that "security theatre," as he terms it, isn't always wasteful, because sometimes it makes our perception of our security more closely match the statistical reality. That is rare—most of the time it throws money away and skews our perceptions further from reality—but we do also have to take into account how safe we feel, as well as how safe we are.

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