The Prisoners’ Dilemma & Bicycle Helmets
OK, so here’s the Prisoners’ Dilemma:
Two guys are arrested on suspicion of being the pair behind an armed bank robbery. The investigating officer is cunning though, and separates them, making each an identical offer:
- Confess to the robbery, and thus provide the evidence to put your accomplice away for a long stretch, and we can cut you a deal - you’ll get to walk free.
- This works the other way - if your accomplice rats on you, he walks, while you take the rap.
- If you both confess, well I get TWO convictions, but I’ll go easy, and won’t object to early parole.
- If neither of you confess, then all I’ve got is this minor* possession of a firearm charge that I can stick on you both. But it’s nothing really, and you’ll both walk.
One of the things I teach in businesses is negotiation, and we use a variant of this as a game to help people understand the value of trust. The basic lesson is that there are good reasons for doing what’s right for yourself, but there are better reasons for doing what’s right for everyone.
Anyway. Bicycle helmets.
Over the last couple of weeks there’s been a low level flame war on the helmet issue running in the comments of the Yehuda Moon strip.
I generally don’t wear a helmet, as it’s just another thing to fuss with, it leaves my forehead sweaty & red when I get to meetings, and I question their magical life-protecting properties under most circumstances. I also worry about the message that the kind of ‘thou shalt wear a lid’ you hear from some quarters sends about the risks & rewards of riding a bike.
Because the risks are small (see below), while the rewards are huge - better overall health (like that of someone ten years younger), and life expectancy that’s overall two years greater than people who don’t cycle regularly.
But I also do believe that the potential upside of helmets is greater for different kinds of cycling. People who are just learning to ride a bike fall off quite a lot in their first few hours; people doing proper off-road stuff over lumps & bumps; BMX kids defying gravity doing jumps and tricks; people racing where they push the physics of cornering & braking, and particularly when they do this in groups or where fatigue is likely to become a factor.
But for the kind of cycling that uses a bike as a simple, pleasant form of transport? No, I don’t believe that the benefit’s particularly significant.
So I’ve been thinking about it more and more, and I think I can frame the helmet thing in similar terms as the Prisoner’s Dilemma:
- If I wear a helmet, then I may gain some safety benefit in the event of a fall. Potentially you get a downside if I don’t tell you about my new helmet-wearing ways, as the hot-shot legal team representing the driver who nearly killed you when he ran you over will now claim that your injuries were caused by your contributory negligence.
- If you wear a helmet, then you too might gain some benefit. And if I don’t know about your new ways, then I’m open to the ravages of the hot-shot lawyers.
- If every cyclist wears a helmet, then we all gain the same potential benefit. But we are all bear the other costs of this (both financial in buying the helmets every two years (explanations here and here) and social as I’ve explained above), to try and avoid something that is incredibly rare.
- What if neither of us wear helmets? There’s an obvious potential downside, as neither of us have anything between our heads and the tarmac in the event of a fall, or the windscreen of a car that hits us. BUT we do get to ride our bikes, and be seen to be doing so by the car-obsessed people around us. We can turn up to meetings looking smart in normal clothes, if not a little flushed (but never sweaty). We can use a bike to pop to the shops without worrying about another damned thing to carry around. We can show them all that it is a perfectly normal, safe thing to do. And maybe get more people to ride their bikes. Because of all the stuff you read on the Internet, all the statistics that the pro- and anti-helmet people YELL AT EACH-OTHER, the one that they all seem to agree on is the simple fact that there is safety in numbers. In societies where more people ride bikes, the accident rates are far lower. And at times of crisis, when people are driven out of their cars and onto two wheels (like, the ’70s oil crisis, the immediate aftermath of the London Tube bombings, and the gas price jump of 2007/8), accident rates drop.
So, this is the crunch. Do we take the prosecutor’s offer of looking after ourselves? Or do we take the counter-intuitive, potentially not best for the individual route, which may ultimately yield the best overall result?
Please do feel free to comment. But no shouting!
(As I write this, I’ve a feeling that it can’t be original - surely someone else has made this connection? If you have, and I’ve read it but then forgotten it on all but a subconscious level, please post a link below!)