Incorrect at least for Denmark and USA [0-1].
[0] https://www.forbes.com/sites/carltonreid/2019/05/10/cyclists...
[1] https://usa.streetsblog.org/2018/01/03/study-cyclists-dont-b...
[0] https://www.forbes.com/sites/carltonreid/2019/05/10/cyclists...
[1] https://usa.streetsblog.org/2018/01/03/study-cyclists-dont-b...
In the US, for experienced/aware/agile cyclists who ride often and defensively, it's usually safer for them to not wear a helmet because:
i) Vehicles statistically give helmet-less cyclists more space.
ii) Unconscious personal safety anxiety and risk-aversion that comes along with a rational cyclist not wearing a helmet. Something they must never forget.