A bit of both but I’d say mostly experience

both

1st the experience
And then some because of the age.

I would have to say a little of both for most people.

experience

Both

Rather experience than age but neither guarantees it. Some people can experience truly a lot but still are emotionally stunted.

experience!

both. a privileged adult may lack maturity. a child may be mature for their age due to their hardship but that doesn't mean their brain is done developing

Both.

With recognition of reality and the order of things..

Early childhood trauma can often fast age them, so I say experience, age often does not factor as many adults lack life experiences and fail to properly mature, some even refuse to grow up, something I call the Peter Pan Syndrome.