18 is the age of majority, or maturity, in most countries around the world. Depending where you live, it might be when you can vote, buy alcohol, or get married. But what's so special about 18 that makes it the beginning of adulthood?

CrowdScience listener Lynda didn't feel very mature back then. She recalls a difficult decision that made her wonder what science has to say about when we’re truly grown up. How developed are we, physically, mentally and emotionally, by the age of 18? And how much does this differ between people, or from culture to culture?

Presenter Caroline Steel digs around for answers with the aid of neuroscientist Sarah-Jayne Blakemore, biological anthropologist Barry Bogin, and cultural anthropologist Bonnie Hewlett. And even some teenagers.

Contributors:
Barry Bogin, Emeritus Professor of Biological Anthropology, Loughborough University
Sarah-Jayne Blakemore - Professor of Psychology and Cognitive Neuroscience at the University of Cambridge
Professor Bonnie Hewlett - Associate Professor, Cultural Anthropology, WSU Vancouver

Presenter: Caroline Steel
Producer: Richard Walker
Editor: Cathy Edwards
Production Co-Ordinator: Ishmael Soriano
Studio Manager: Neva Missirian