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Why ‘photo-ID’ is not simple

I am fairly seriously prosopagnosic. That may be why I am so skeptical about identification in general, but the research into the condition is beginning to militate quite strongly against the presuppositions many people in the law-and-order business make about the utility of photo-ID.

The BBC has an interesting radio programme on how bad people are at facial-recognition, here:
Health Check

The points in this that I suggest are important for policy are:

1. Most people are not in fact very good at matching strangers to their photographs. People tend to be much better at recognising people they know than people they do not know, and mistakenly generalise what you could call ‘Easy Matching’ from their experience with their familiars. This is not a mistake you would make if, like me, you find recognising people you know hard.

Looking at someone’s ‘photo-ID’ on a one-off occasion will ordinarily be hit-and-miss, unless you are one of the rare people the radio programme calls “super-recognisers”.

2. A significant number of people (the programme suggests 3%) are sufficiently bad that it handicaps them in everyday life, but generally they do not realise it. I was 30 before I understood I had a problem, though I can recall incidents back to 6 or 7 years old that are examples. Yet officialdom assumes that anyone can recognise others from pictures, to the degree suggested by the false Easy Matching supposition. There is no testing of passport control staff, police, security guards, bar-staff… anyone, who is expected to do the matching.

Yet 3% or thereabouts not only are ordinarily useless at it but are being put to an impossible task. They may well compensate intuitively by responding to other behavioural or bodily clues that have nothing to do with facial features—the Clever Hans syndrome. I know I do. But I was not always aware that is what I was doing, or that I was different in that respect from other people.

Some Hypotheses:

Photo-ID for age-checking is rather like voice-stress or polygraph “fraud detection”. There is no real evidence for its accuracy, yet the story that it ‘obviously’ works is so plausible to so many, that few even question it. There is a massive confirmation bias, and it is probably not acting as more than an intimidatory deterrent.

Software facial-recognition is thought of as pretty bad for the purpose that it is put to (fact) – but it may well be better than 90%+ of people under the same circumstances of matching strangers in large numbers, and infinitely better than the small fraction of checkers who, unknown to themselves and their employers, are getting it wrong almost all the time. Criticisms of the technology are often as based in the mistaken Easy Matching idea as support for it. Both sides of that argument assume people are better than machines. But in practice ID-ing travellers and drinkers doesn’t do a lot. It is an imposition and a cost on everyone, but the attitudes struck in security theatre do not stop competent imposture.

Flash and dash is close to useless, but there’s a huge industry of ID badges built on it. The false assumption is that replacing a doorkeeper who knows everyone (and in most cases will therefore recognise them quite well), with picture-passes that ‘anyone can check’, is more efficient and more secure. Quite the reverse. But look at the reception area in any large firm and what to you see? Picture passes with RFID tracking of the pass and bored temps concerned that you display a badge properly, operating on the assumption that your badge is you.

(Technology keeps ever more track of those tokens, however. So, as long as you are compliant, regardless of the fact that linking ID with people does not work, ID does work as surveillance.)

There is now in the system a prejudice and an interest in not facing (ha!) these ideas. Everything in fact tends towards dismissing them. The authoritarian mindset is particularly prone to confirmation bias (Cf. the catastrophic DNA database arguments), and Clever Hans will sucker them every time. The most modern fashions in government are close to superstition.

6 comments to Why ‘photo-ID’ is not simple

  • Bruce Hoult

    I’ve never actually tried it, but it seems intuitively obvious that if you want to use fake photo ID you should choose someone with kinda the same shape face, but something easily changeable that is wildly different. The most obvious is someone who differs from you in haircut or facial hair.

  • Confirmation bias: presumably this is the feeling you get when you don’t want to fail someone’s ID (particularly on a busy bar or checkout) because of the delay and unhappy customers in the queue behind it will entail?

  • Maureen

    Or confirmation bias could be just assuming that everything is okay, and that nothing will ever happen. Or that if someone looks different from their ID, it’s just another bad or old ID picture.

  • guy herbert

    No; confirmation bias is a well-established term. It means the tendency to prefer information or reasoning that confirms an existing belief and to ignore, fail to look for, or discount evidence and arguments for a contrary or null conclusion.

    What Maureen describes could be an incidence of confirmation bias, but what I was alluding to is the tendency of people, particularly people in authority to believe that because X is usage, X is useful. Most people are prone to confirmation bias – even to the point of perverse reverse interpretation of evidence, seen at its most obvious in conspiracy theoretical worldviews – but official authority is particularly bad because admitting it is wrong weakens institutional power as well as embarrassing individuals, and because group solidarity reinforces the established viewpoint.

  • Andrew Duffin

    “The most modern fashions in government are close to superstition.”

    Amen to that.

    Global warming springs to mind…

  • On one of those reality TV shows about UK border guards, I remember seeing a situation in which there was suspicion about the validity of the passport, so they took a photo of the suspect and compared the two photographs. This, it was explained, was much easier than comparing a photo to a person. So border security people are probably fairly aware that photo-ID isn’t much use. It’s security theatre, after all.