its been said that cyclists wearing helmets makes people wary because it makes them think cycling is dangerous.
This is therefore a contradiction to risk compensation (taking less care) when cycling. How can a helmet make people think it is more dangerous but take less care? Surely its unreasonable to consider it can do both?
Not necessarily, because it's not necessarily the same person thinking that cycling is dangerous that thinks they can be more careless when wearing a helmet.
Imagine, for instance, a parent taking their teenaged child to school and close-passing a commuting cyclist who is wearing a helmet.
The parent may think that cycling is dangerous on busy roads, because cars (just like the one they are driving - school run parents don't always get irony) "have to" pass close to the cyclist to overtake. The worried parent then makes the teenager wear a helmet when cycling.
The teenager now has a "safety device" that their parents tell them they need to wear, and they are already over-flowing with invulnerability, so they may consider themselves to be even more immune to any danger when wearing a lid.