Study finds that wearing a cycle helmet may diminish ability to assess risk

[Mike Sales]

It is a diversion and an alibi for the chief cause of the danger, of which you are well aware. And the evidence is that helmets do not work in reducing that danger.

Agreed on the first point.
But then questionable lab studies don't prove that my choice to wear one in case of falls (I'm under no illusionment that it would do anything for me in a head-on collision with a HGV for instance) increases that danger.

Unless there is zero protective effect in helmets there must be something which reduces their overall effectiveness to undetectable levels. My guess is Risk Homeostasis.
You might to like to read this from the BMJ by Ben Goldacre, Wellcome research fellow in epidemiology and David Spiegelhalter, Winton professor for the public understanding of risk.

https://www.badscience.net/2013/12/bicycle-helmets-and-the-law-a-perfect-teaching-case-for-epidemiology/

In any case, the current uncertainty about any benefit from helmet wearing or promotion is unlikely to be substantially reduced by further research. Equally, we can be certain that helmets will continue to be debated, and at length. The enduring popularity of helmets as a proposed major intervention for increased road safety may therefore lie not with their direct benefits—which seem too modest to capture compared with other strategies—but more with the cultural, psychological, and political aspects of popular debate around risk.

"Too modest to capture!"

[poetd]

"Too modest to capture!"

I keep my reflectors on.
0.00001% safer?
Still taking it.

[poetd]

Some cyclists spend thousands shaving the odd gram off here and there to increase speed.

If you told me a pocket full of heather would make me 2% safer on the road, I'd have heathery pockets.

[Paulatic]

The last few weeks I’ve been getting Mrs P cycling she has a helmet but I said you don’t need to wear it. I’ve not got her over 6 mls yet and avoiding big hills. She still brakes when going down hills and I wait patiently at the bottom for her. Out last week and when she got to the bottom said,"I’d go faster down the hill if I was wearing a helmet". Need I say more

[Mike Sales]

"Too modest to capture!"

I keep my reflectors on.
0.00001% safer?
Still taking it.

Me too. But the question of helmets is vastly different. The emphasis laid on helmets by so many people, so many authorities implies that their effectiveness is not trivial, but crucial. They are a serious diversion from interventions which might work, for which there is good evidence in other countries, to an intervention for which there is no good evidence. Why is this one wonders? I am afraid I am cynical enough to think that it is because helmets put the onus on cyclists to do something even if it does not work, and divert attention from measures which might inconvenience those who actually make the roads dangerous.

[Mike Sales]

Some cyclists spend thousands shaving the odd gram off here and there to increase speed.

If you told me a pocket full of heather would make me 2% safer on the road, I'd have heathery pockets.

That is up to you. I am not superstitious.
I have been bothered with almost no propaganda advising me to lighten my bike.

[yostumpy]

its probably ''Volvo driver'' syndrome.

[Mike Sales]

its probably ''Volvo driver'' syndrome.

I think so. More usually called Risk Compensation, or more accurately, Risk Homeostasis.

[pjclinch]

If I'm sat in a comfy lab, I'm not feeling in much danger and so might be more susceptible to unconscious biases through lack of awareness of the risk due to set and setting.

When I'm cycling through the City centre dodging traffic and idiot pedestrians, I'm on full risk alert, helmet or no.
In that situation I'd venture that the effect of this unconscious bias is lessened.

Nobody is suggesting it's a perfect experiment. Part of the issue with helmets is that designing good experiments is very hard, designing perfect ones is impossible. The trick is seeing where imperfections confound the experiment so much as to be useless (step forwards Thompson, Rivara & Thompson!) or not. We all tend to dismiss things we don't like the sound of: human nature, cognitive bias. Stripping that away is hard.

You say you're on "full risk alert", but that isn't anything like the same as avoiding risk. You have accepted you're in a risky environment so rather than avoid risk you are choosing which ones to take. "Can I filter down here before the lights change?";"If I sprint here will I get across in time?". Being on high alert is just another thing that might actually increase risk taking...

This is simply one study of a growing pile that suggests wearing PPE encourages risk taking. I'd want a bit more evidence than it not fitting my preconceived notions of what's good for me before dismissing it.

"Risk" by John Adams is an eye-opening read, now available as a downloadable PDF. Worth a read.

Pete.

[poetd]

This is simply one study of a growing pile that suggests wearing PPE encourages risk taking. I'd want a bit more evidence than it not fitting my preconceived notions of what's good for me before dismissing it.

No problem at all with that, except I'd like more honesty in science in general to be honest, but especially studies like this that will lead to yet more banner waving of this being "Proof helmets are dangerous!" from certain quarters in the cycling world.

Given the setup of the experiment, why aren't they claiming that having your eye movements monitored increases risk taking?

Do they mention or mitigate for that difference between the subjects and the control?

No.
Shows a bias inbuilt into the results and therefore the conclusion.
The study in no way proves anything related to cycling helmets affecting risk taking behaviour - as it could easily have been any kind of headwear and rather than being the form of headware it was the presence of the mounted camera that affected the behaviour.
You could easily design an experiment to measure the effects of different kinds of headwear, but they didn't and so their results have less validity as a result.

[Wanlock Dod]

Given the setup of the experiment, why aren't they claiming that having your eye movements monitored increases risk taking?

You might find this study interesting, they showed that wearing a cap instead of a helmet did not have the same effect (perhaps because caps are not protective).

Do you apply the same level of scrutiny to studies that suggest that helmet wearing is beneficial?

[poetd]

Do you apply the same level of scrutiny to studies that suggest that helmet wearing is beneficial?

No.

I took an active decision that because head protection is available I would avail myself of it based on no studies or other scientific literature.

There are no studies done that say jumping off a cliff with a parachute is safer than jumping without one.
Doesn't mean I'm going to chose sans-parachute just because of the lack of studies.

[Mike Sales]

Do you apply the same level of scrutiny to studies that suggest that helmet wearing is beneficial?

No.

I took an active decision that because head protection is available I would avail myself of it based on no studies or other scientific literature.

There are no studies done that say jumping off a cliff with a parachute is safer than jumping without one.
Doesn't mean I'm going to chose sans-parachute just because of the lack of studies.

If cliff jumping were a regular pursuit, and a few of these jumpers died, it might seem obvious that parachute wearing was a good idea.
If then parachutes were made obligatory for cliff jumping or campaigns vastly increased the proportion of jumpers wearing them, we might expect greatly reduced mortality for these lemmings.
However, if the reduction in mortality was "too modest to capture" in our statistics, a rational observer might begin to doubt that parachutes were an answer to the problem.
This study is an attempt to find out why helmets do not bring about any reduction in cyclists' mortality.
They do bring about a reduction in cyclists though.
Some of the loudest voices calling for parachutes come from those who are pushing people over cliffs. A more obvious solution to the growing pile of dead bodies at the bottom of cliffs might be to stop pushing.

[Wanlock Dod]

I took an active decision that because head protection is available I would avail myself of it based on no studies or other scientific literature.

Do you take the same approach and wear protective equipment when walking, driving, drinking alcohol, and using stairs? If not why not? Is there something especially dangerous about cycling?

[poetd]

Do you take the same approach and wear protective equipment when walking, driving, drinking alcohol, and using stairs? If not why not? Is there something especially dangerous about cycling?

Yes I do.
And yes, cycling in traffic carries risks. You'd have to be an idiot to think otherwise.
And as a grown up I'm happy to accept personal responsibility for my own safety and actions, I take precautions I feel are sensible for me to take rather than crying at everyone else about victim blaming like a pathetic child.