Why did some states change their laws for the requirements of motorcycle helmets?

Why did some states change their laws for the requirements of motorcycle helmets?

A few states changed their laws from being required to wear a helmet while operating a motorcycle to being required to wear a helmet when what is usually under 18 years of age. Why?
What influenced their decision? Was it because they simply didn’t want to wear a helmet? What about unintended concequences?
Also, why would they

How well do helmets protect your head in a motorcycle accident?

How well do helmets protect your head in a motorcycle accident?

I am interested in seeing if there is any correlation to wearing a motorcycle helmet and reduction of injuries in an accident.
Well what about the fact that helmets cause you to be classified as legally deaf and blind?

motorcycle helmets?

motorcycle helmets?

i noticed that some people that wear motorcycle helmets wear helmets that dont cover the face. it looks like a ww2 german army helmet. is this safe to have on when going on the freeway?

Links to online videos about motorcycle helmets?

Links to online videos about motorcycle helmets?

I would like to know links to online videos about motorcycle helmets. The video must be able to be played or downloaded online. Any aspect of the topic will suffice. Note. I am NOT looking for stunt videos taken from helmet cams! I am looking for informativeness, not show-off-ness.
Thank you. The best one will get

What are the differences between ATV and motorcycle helmets?

What are the differences between ATV and motorcycle helmets?

What are the fundamental differences, and what are the reasons they’re different?
In a pinch, can an ATV helmet be worn when riding a motorcycle, or is the protection it offers somehow unsuitable for motorcycle riding?
Thanks!