My daughter is doing a medical degree. At dinner the other day, I mentioned that a few years back everybody seemed to think that doctors would be replaced by expert systems. Did that happen? Oh no, she said, that’s never going to happen. Its the doctor’s job to decide. Hmm. I see a scientist’s job, much of the time, as a dogged persistence in avoiding deciding, as you hunt down the sometimes stubborn truth. You have to steer carefully between the Scylla of shallow herd fashion and the Charybdis of renegade self delusion, but the aim is constant – to discover what really is the case.
Of course we have statistical methods for dealing with uncertainty, whether it be missing information or true randomness. But even here, as scientists, we avoid jumping to a conclusion, as a fundamentally unsound thing to do. All I can do is tell you that on Hypothesis A, you would have been pretty unlikely to get that measurement. Doesn’t necessarily mean its wrong though… (Pour beer. Cue usual frequentist vs Bayesian argument. Fail to come to conclusion. Drink more beer.)
But for much of our worldly lives, its not about truth, and its not about decision – its about action. You can see this trio as a chain. You cannot take a sensible action unless you have made a wise decision. You cannot take a wise decision unless you know what is and what is not. Each step limits the landscape for the next, but does not fix the path. Well thats what Hume said, which is good enough for me, as he is an Edinburgh Local Hero. Got a statue on the High Street and everything.
We see this every day in public policy – should we punish Assad? Should we allow fracking? Anybody care to postulate the relevant probability distributions in the Syrian case? Thought not. What makes these debates so difficult is not just that we have to act before all the options or their consequences are clear; or that we have to decide whats going on before we know all the facts; its that different people are not even trying to achieve the same ends; and sometimes they don’t even realize this.
A curious and frustrating example is racial profiling. If your aim is to maximise the number of terrorists you stop, regardless of anything else, its hard to deny the statistical fact that if you randomly stop young asian looking men with beards you will do better than if you randomly stop middle aged white women. But if your aim is to minimise the number of terrorists you create over a period of years, you could be making a big mistake.
A few days back, I followed a Twitter link to this beautiful little video. A black American woman explains how she was asked out of the blue for two types of ID, and looked up in a bad-check book, at a supermarket checkout. Her white sister in-law, immediately in front of her, was not asked for ID. The sister used her white privilege to step in and address the inequity, which is the political point of the story.
However what I found intriguing is that the woman telling this depressingly normal story is so clearly middle class, articulate, intelligent and trustworthy. It sounds like the checkout girl was not being mean, but dim. At the back of her head was not necessarily emotional dislike, but instinctive statistical reasoning – if I stop black people, I will find more bad checks. Well this is probably true, but its a bit like the old gag about the price of fish in Billingsgate market being correlated with the size of women’s feet in China. Most bad checks will be written by members of the impoverished underclass. Due to hundreds of years of social, economic, and political repression, black people in the USA make up a larger then average fraction of the underclass. But the woman in that video is patently not a member of the impoverished stressed out underclass. So what’s depressing is that this isn’t obvious to a supermarket checkout girl. Why can’t she read the signals?
So.. I guess education, in the largest sense, is the answer. Maybe we can’t avoid profiling. We just want better profiling. Academic readers can draw the analogy with citation statistics and divert the conversation as they wish.
Anyway. Got some grant applications to re-read.
