14 or 15, often. 18 year old adults is a recent liberal human rights innovation. There's not a whole lot of difference between humans now and humans 100,000 y

14 or 15, often. 18 year old adults is a recent liberal human rights innovation. There's not a whole lot of difference between humans now and humans 100,000 years ago. We have better tools and culture and knowledge, but we're physically identical - swap a baby in either direction and nobody would know the difference.