From Missed Travel To Bad Habits: 29 Regrets People Have From Their 20s

In a legal sense, adulthood is primarily a cultural question. It reflects when a society believes young people become sufficiently competent to do certain things and can vary from country to country or, in the US, even state-to-state.

Depending on where you are in the US, people may be able to start driving at 16, 17 or 18. The US allows people to sign up for military service at 18, but only allows alcohol consumption at 21 years of age. In Europe, many countries allow alcohol and tobacco consumption at 18, but a few allow people as young as 16 to legally consume alcohol.

The question of marriage and consent is also an important and touchy subject. While some cultures and religions around the world may embrace a younger standard for marriage or even parenthood, most of the West considers people to be fully mature at 18. This viewpoint embraces not just physiological aspects, but psychological, emotional, and legal considerations as well.

But what does science think? Well, most of us reach the peak of our physiological development in our early to mid 20s, and our brains stop developing by around age 25. Our capacity for logical reasoning develops at around age 16, but much of the other mental characteristics we need to successfully navigate life can appear later.

Some like to point out that people in the past were forced to mature much faster than adults in the West are today. That may be true for people living in rural areas or subjected to pre-child-labor-law industry, but it wasn’t universal.

In a fascinating piece in The Atlantic, the author reminds us that famous author Henry David Thoreau published his first book at 31. Until that time, he had been quite aimless, living with parents or friends and working any job he could get his hands on.