Earlier quoted context omitted.
As an American, whenever I see articles about Dutch cycling culture, the thing that stands out to me is that nobody is wearing helmets. In the US, I wouldn't dream of doing that - it's just too dangerous, because there's too much risk of being involved in a high speed collision. But, after having spent some time in the Netherlands, it's come to feel like a minor injustice every time I put my helmet on. It's a little…
I believe in countries/cities like these its safer to not use a helmet. Drivers see that your being unsafe and give you much more room and are more aware of you. Less accidents and less deaths in total by not wearing a helmet! I couldn't find the study that was posted on hn, but there are lots of articles.
https://bigthink.com/neurobonkers/the-bike-helmet-paradox
The short answer is, "wear a helmet if you have one, and try to get one, but if you don't have one, you should still bike anyway."