Friday, November 21, 2014

Serial science

Are you hooked on Serial yet?  The current season of this radio series from the makers of This American Life explores whether Adnan Syed, in jail for the last 15 years and sentenced to life for killing his ex-girlfriend Hae Min Lee when they were both 18, really did it.  He says he didn't.  His friend Jay says he did.  The question comes down to, what happened in those crucial 21 minutes when his whereabouts are unknown and undocumented, and Hae was strangled?

Sarah Koenig, presenter of this series, and a producer of This American Life, describes herself as having been obsessed with this case for the past year.  She probes every angle, reads every report she can find, listens to the police interview tapes, talks to anyone who will speak to her about what they saw or what they know, revisits the supposed scene of the crime, tests whether Adnan could have gotten there in the 21 minute window of opportunity, challenges Adnan with her thoughts, doubts and questions in hundreds of phone calls, and so much more.
What she realized is that the trial covered up a far more complicated story, which neither the jury nor the public got to hear. The high school scene, the shifting statements to police, the prejudices, the sketchy alibis, the scant forensic evidence - all of it leads back to the most basic questions: How can you know a person’s character? How can you tell what they’re capable of? In Season One of Serial, she looks for answers.
Some weeks Koenig is convinced Adnan is guilty, some weeks she's not so sure. We don't yet know what she concludes, or indeed whether she concludes anything other than that it's impossible to reach a conclusion, but, perhaps because it's possible to weigh the evidence from various angles, it's a gripping series.

Scales of justice; Wikipedia

A compelling story.  Not because we really care about Adnan -- unless he's innocent, in which case of course, the injustice is a tragedy.  Indeed, it's Hae one really cares about, a bright young woman whose future was violently and callously taken from her.  And, the idea that, to compound this tragedy, a young man's life may have been ruined by a system that didn't do it's job is also part of the emotional hook that keeps us listening.  But more, to me the show is fascinating because of what it tells us about truth, and how we know what we know.

Starting with the Enlightenment around 400 years ago, the gold standard for science has been empirical evidence, the equivalent of fingerprints, witness stories and DNA.  Naturalists collected then, scientists collect now, observational or experimental data, to try to make sense of, and build a story with.  As Koenig does, scientists assume there's a truth, and that evidence can lead us to it.  Yes, the evidence needs to be tested and weighed, and evaluated and re-evaluated, but the assumption is that with evidence we can know the truth.

But that's science. Koenig is talking about a legal question -- this crime happened, who did it? Lawyers aren't necessarily looking for the truth, even though they know there is one, because they know they can't necessarily know what it is.  The evidence often can be interpreted in numerous ways, used by a canny defense attorney as well as a canny prosecutor in support of either guilt or innocence.  Or, as in Adnan Syed's case, it seems that what would be crucial evidence just doesn't exist, so he was convicted on circumstantial evidence instead.

And of course sometimes pieces of evidence are omitted in the pursuit of a consistent story, which is often what lawyers are really after.  Many times, defense lawyers don't know whether their client is guilty or innocent, but they simply (or not so simply) build whatever exculpatory story the evidence (or some of the evidence) will support.  So, Koenig is being an ace reporter in this series, and a great storyteller as she unpeels layer after layer after layer of evidence in her search for the truth, but she's not necessarily being a winning lawyer.  But that's ok; she is a reporter.  By contrast, in our system a lawyer's job is to take sides, not to seek truth, which is different from science and might seem strange unless you realize that there may not be a better way, to determine guilt or innocence  when truth can't be tested directly.

Chemical balance; Indica Scientific

Scientists are telling stories from evidence, too, with the hope that there's a knowable truth to be found.  As much evidence as they can get.  Should they be impartial?  Yes and no.  Building evidence is what the whole push for Big Data, and meta-analyses is about; building stories from enough data that we can assume we're approaching the truth.  Evidence that should be weighed impartially.  This seems like the new path to truth but, to be fair, Darwin collected Big Data in his way, too, observing more pigeons, barnacles, and orchids than most of us would have had the stomach for.  He was a diligent, patient observer, who also built a consistent story from the evidence -- but with various theories in mind.  Not impartially.  So, scientists are reporters of the natural world, but the synthesizer scientists are lawyers, too, piecing together the evidence to make a good, consistent story, taking a side.

But, it's never clear how close we are to the truth, even if or when we think we can assume there is a single truth.  Understanding what genes are and what they do, for example, took a lot of sleuthing, building a story, from the circumstantial evidence that Mendel so diligently provided, to the discovery that chromosomes were an important actor, and the discovery of DNA, and so on.

But geneticists understood what genes were a lot more definitively in the beginning than they do now. Ironically that was because it was before there was so much evidence.  Ask 5 of them now what a gene is, and if any of them actually give you an answer it will be vague, and it's likely that it won't agree with any of the others you get.  Ken always told his Human Genetics students each semester that much of what he was going to tell them wasn't going to be true the next year.  They seemed surprised or nonplussed, but he then explained about our growing knowledge and understanding.  Presumably there's a truth, and presumably we're heading toward it, but often it seems we have no idea how close we are getting to it.  Of course, the goal keeps changing as discoveries keep happening, and that doesn't help.

We don't yet know how Sarah Koenig is going to conclude her story.  She will have plowed through masses of evidence, but if the truth was in there to be found, I think it would have been found 15 years ago.  She's talking to a lot of people who knew Hae and know Adnan, and perhaps she'll dig up something new and significant that might change the story.  But so far, the crucial evidence is missing; only Adnan, Jay and Hae know what happened, but Hae can no longer speak, there were no witnesses, and Adnan and Jay are telling different stories.  Or, maybe someone else killed Hae.

This is an imperfect metaphor for science, of course, because no one person is holding out on us on whether there are multiverses, or dark matter, or something crucial missing from our understanding of biology, or even how antimalarials work.  But the elusiveness of these kinds of truths, the difficulty of interpreting the evidence and the idea that we might need to re-evaluate the data from time to time certainly pertain to science.

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