Remember kids... always wear a helmet. (The almighty bikeradar helmet thread)

Surely wearing a helmet is encouragement - I am still waiting for a few of the anti-helmet brigade on here to clearly and unequivocally state that the helmeted are a symptom and in no way part of the problem. But I am not sure that they can do that honestly because everything you do has consequences, and wearing a helmet has the consequence of normalising it, and normalisation is encouragement.

It's entirely possible that they are a symptom and part of the problem, there is obviously a vicious circle here. But people wear helmets for different reasons: maybe they're cycling to a race, maybe their commute ends in an off-road section, maybe it's just habit from a time when they did some mountain biking (like me), maybe it keeps their head warm or gives them somewhere to mount an extra light. It's worth noting, however, that all of these reasons are about the wearer, none of them are about encouraging other people to wear a helmet (or recommending/urging etc.) So, unless you make assumptions about the wearer, using a helmet doesn't normalise or encourage the use of a helmet for standard, unhurried, A-to-B cycling.