When you see one of those things, you can hover over it to see what was typed, and there is also an emoji cheat sheet. 
Just look at it!
Yet I doubt anyone feels the need to investigate whether 13 year olds are capable or incapable of driving. It’s easy to recognize the truth is between the two: most could somewhat, some better than others, on average with less ability and need than 18 year olds.
Setting policy is a different matter than trying to understand reality. Reality is often analog, and going in with the aim of drawing lines is saying you plan to ignore that. We evolved from invertebrates, our responses and theirs are derived from the same, and I don’t think it helps us understand the details to pretend there wasn’t a continuum there.
Yeah. I do think the differences in degree matter in what’s justified; I would crush a biting mosquito to protect my arm, and never a scratching cat. But recognizing that living things feel damage in their own ways, and so not inflicting it needlessly, seems a better base than to try and invent a point where you could torment things without reproach.
