[bluGill]

If we do, over the next 10,000 years it will make a difference in human reaction times. Assuming of course that nothing else destroys us all first, or makes cars obsolete.

Since I don't have 10,000 years I prefer to make cars obsolete.

[ironmagma]

It has nothing to do with how long you personally have; this is about the species, remember? You could very well die from lack of airbags, and not because you had a slow reaction time but because your skull isn't optimized for surviving collisions. Further, there are a lot of stand-up people you currently like who would die. There are many reasons to protect the weak, even from an evolutionary standpoint.

[bluGill]

I don't have 10,000 years, the species probably does.

Evolution doesn't care. There are also reasons to not protect the weak. Either way it changes the future of the species. On one hand we don't protect the weak, and thus the strong survive; on the other hand we protect the weak, the species doesn't get as strong, but we can encourage some other trait(s).

Note, strong species might be a stronger skull, better reactions, or something else that I can't even think of. I don't know how to force any choice.

[ironmagma]

The point though is that making ourselves dumber by making our skulls thicker so we can survive car crashes is a bad choice. We want to be getting smarter, not dumber, right now. Our instincts tend to align with that goal (including protecting the weak) when they are pro-social since that’s how we’ve been evolving lately.

[angry_octet]

And it misses the point: the evolutionary change that has already occured includes the ability to put in airbags and eventually self driving cars, not a change in reflexes. Though better intuition about risk might see the species live longer.