There are currently TV adverts in the UK that graphically demonstrate what damage an unrestrained passenger (particularly in the back seats) can do to other occupants of the car in the event of a crash. Particularly memorable is the one calmly describing how the teenage son “sat up on his seat, killed his mother and then sat back down again.”
So there’s very good reasons to make it the law, your actions have a very real impact (no pun intended) on others.
It’s not quite the same for a motorcyclists, though I have to say anyone on a motorbike in traffic without a helmet does need their head seeing to.
Substitute “scarier” or “more intimidating” for “better” and you’d have the situation here in Minnesota.
I used to work at the state Capitol, and let me tell you, the last time the state reps tried to legislate a madatory helmet law, they crumpled in the face of the bikers who roared up to the Capitol steps (literally) in response.
Often, when these anti-helmet biker dudes testified at committee hearings on the bill, they had to be reminded of the severe penalties for making threatening remarks to legislators. (At these hearings I learned that the Sergeant-At-Arms position at the legislature is not soley a ceremonial position.)
These bikers were a bunch of rude, crude, low-lifes. But hey, as a political strategy, it worked!
I first heard of the study in a book titled Armchair Economist by Steven E. Landsburg. The original study was conducted by Dr. Sam Peltzman at the University of Chicago. A bit of Googling led me to an article by Scott Geller, Prof of psychology, Virginia Tech, and senior partner with Safety Performance Solutions.
In a nutshell, studies suggest that protective equipment leads to more reckless behavior. In the specific example of auto safety equipment the use of the equipment resulted in more reckless behavior and more accidents, although fewer of the accidents were fatal for the driver. Fatalities for pedestrians also increased.