Ask Lemmy

It varies but I would say typically around 25. Years 18-24 are still mostly spent coming to terms with adult responsibilities and unlearning oversimplified teenager worldviews.

Life altering events or lack of can influence this one way or the other. Like moving out, starting a relationship, having children or loss of someone close. (Literally anything that makes one re-evaluate ones values and thinking)

Like someone living with their spouse and 2 children at age of 25 will likely act more mature than say socially isolated NEET still living at their parents at age 30. (Not trying to shame with the latter, just pointing out how life experience outweighs age in this)

In my personal experience this happens when you start taking responsibility on.

Society at large depends on members ensuring certain things, even at their own peril, without concepts of fairness and such, so others don't have to worry about negative circumstance affecting them.

The most simple form of that is parenthood and similar concepts. You take responsibility for other live because at first they can't do that themselves. No matter if you are hungry or cold or tired, you will always provide for this life at any cost.

Responsibility can take many forms. Start a business, take responsibility for your employees stable paycheck. Choose a job that society needs done like nursing or such.

In theory every full member of society takes on a little responsibility more or less to their ability which results in a stable social construct.

So I would say: taking on responsibility makes you an adult. I have heard that phrased often as "realizing life is not fair", which usually comes with taking on responsibility for others and yourself.

There are plenty of faux metrics like age. You can find plenty of old people unable to take on basic responsibility. There is plenty of experienced or wealthy or educated people that can't be trusted with anything but maybe looking out for their own interests.

Taking on responsibility has to happen responsibly, nothing worse than taking on too much and drowning while exposing others to negative consequence from that. So taking responsibility for your own life entails realizing that you put your own oxygen mask on first and then start helping others if you have the choice.

When they learn to be ok with cleaning the icky stuff from the sink.

I spiritually felt like an adult at 16, which was also the traditional age of majority here, but then i moved back in with my parents to do university and felt less and less like an adult

I'm definitely more fond of the idea it's a different age for different people. I started puberty early and always felt other people my age were out of step with me - people like me physically and mentally become adults sooner than other people. (But we shouldn't try and use this in regards to consent laws or drinking age, of course)

But the most important consideration is if you treat people well and do things on your own initiative.

According to Ally Sheedy's character in the Breakfast Club, it's when your heart dies.

When you’re seen as an adult by society

It's a gradual thing. People (are supposed to) acquire more and more agency and responsibility as they grow and at some fuzzy point they are the main responsible for their own life. Some people never really get there.

When they gain the appreciation of society, which is childish and whimsical.

Without further definition from OP, I’m worried that this question is more disturbing than we’re all realizing. This is the internet after all