Age of criminal responsibility

When should the age of criminal responsibility start? When does a child become an adult?

I don't think it matters. It's always so dumb when some for instance16 y o kills a girl. Oh golly it's a kid. His brain is not developed. Lets give him a year or less. Who cares if their brain is developed or not. They're demon posessed and dangerous. Protect people. Last year a 9 y o boy got raped and killed by a guy in his twenties who was in and out for years and it was always: oh the poor sweet darling. Lets give him another chance to get even worse.

The idea that there is a magic age where kids all of a sudden understand the gravity of their actions in order to be held accountable is fundamentally flawed. From a physiological stance, we know that most kids don’t have a fully formed prefrontal cortex (the part of the brain that allows us to understand the long term) until roughly age 25. We are physically incapable of really understanding the consequences of our actions before that.

Of course, that isn’t taken into account when we’re legally able to make all sorts of adult decisions by 18 (or younger in some cases.) As for criminal offenses, we really shouldn’t treat any kids like adults.