We've not long got back from a skiing holiday in the Swiss Alps. And one thing that caught my attention (particular as our trip coincided with Michael Schumacher's accident) was that everyone skiing was wearing a helmet. When I was learning to ski 25 years ago nobody wore a helmet. So, how did society go from 0% wearing a helmet to 100% wearing one?
The obvious answers if you read the economic textbook would be that: (i) ski helmets have got cheaper, or (ii) ski helmets have become better - lighter, safer etc., or (iii) skiers are better informed about the benefits of wearing a helmet. Personally, I think we can safely ignore all three of these as the main causal factor. To argue the point I would compare skiing with cycling and rock climbing. Over the timespan I'm looking at here I would guess that helmet usage in cycling and rock climbing has stayed pretty much constant - and nearer to 50% than 0 or 100%. Yet skiing helmets are essentially somewhere in-between cycling and climbing helmets. So, if either (i), (ii) or (iii) are the reason so many people are wearing ski helmets I would expect to see a similar change in the proportion of people wearing cycle and climbing helmets. And that has not happened.
In order to explain the shift in helmet usage I would instead look to conformity. I think the main reason skiers where helmets is because other skiers wear helmets. This can easily explain a shift from 0 to 100%: We go from an equilibrium of no one wearing a helmet because no one wears a helmet, to an equilibrium where everyone wears a helmet because everyone wears a helmet. It is also easy to explain the difference between skiing and cycling and rock climbing: A ski resort is a 'confined space' where you are surrounded by skiers wearing helmets, while a cyclist or climber can easily not meet other cyclists or climbers all day long. This lack of exposure to others can be expected to dim the influence of conformity.
But what does conformity really mean? It is tradition to distinguish between informational conformity and behavioural conformity. Informational conformity would say you wear a helmet, on seeing others wearing them, because you think they must be well informed on the safety benefits of wearing helmets. Behavioural conformity would say you wear a helmet so as to not be the odd one out. My hunch is that a third type of conformity is also at play here - I will call it reflectional conformity. And the basic idea is that seeing others doing something different makes you reflect more on your own decision. So, seeing others wearing helmets makes you reflect on the potential losses of you not wearing a helmet. This means that your choice is not directly influenced by observing others. It is more that observing others doing something different indirectly makes you reflect much more on the decision you are making. And when you think about, a helmet definitely seems worth buying.
As far as I am aware reflectional conformity is a new idea. But I can point to some evidence it exists because in a recent experiment with Thomas Singh we saw clear signs of it. The experiment was set up to see whether subjects were more cooperative if they saw what others were doing. We found that observing what others were doing had a big effect on cooperation. And it do so because subjects were more responsive to own experience. In short, what we saw looked much more like reflectional conformity than behavioural or informational conformity.