True, but it's a lot worse for folks who haven't fully developed the part of their brain that is responsible for things like complex planning, impulse control, emotional regulation, logical thinking, the evaluation of risk and the awareness and careful consideration of long-term consequences.

Not that I'm saying that teenagers can never do those things or that adults always will, but because their brains are still developing teenagers are, on average, going to make mistakes and take risks much more often than adults past their mid 20s, and that's without even taking into account the flood of hormones and the additional stress of adolescence. Making mistakes and taking risks is just a normal part of growing up, and some people feel that it's even advantageous for young adults to be prone to recklessness.

Depends on the human...either the one making the 'biologically predisposed' bad decision, or the one judging it.

I think you completely missed GP's point. Teenagers ARE much more likely to make a bad decision than other groups.