In some ways the 21st century is a very unusual time when it comes to adolescence - a study in the US found that teenagers smoke less, drink less and have less sex than the previous generation. And worldwide young people are coming of age in a digital era, with the dangers and opportunities that represents. Our expectations of teenagers vary hugely depending on the social, historical and cultural context. Paleoanthropologist Ella Al-Shamahi takes us through the big evolutionary questions about adolescence: Why do humans go through this developmental stage? What's the point of all that teenage angst? And how come every generation stubbornly repeats the same mistakes?

She is joined by a panel of experts:

Laurence Steinberg is one of the world's leading experts on adolescence. He is Professor of Psychology and Neuroscience at Temple University in Philadelphia, USA. His latest book is called, 'You and Your Adult Child'.

Emily Emmott is a lecturer in biological anthropology at University College London. She's currently researching the implications of the social environment around us during our teenage years.

Jon Savage is a British writer and music journalist, best known for his history of the Sex Pistols and punk music. He's the author of 'Teenage: The Creation of Youth Culture'.

Brenna Hassett is a bioarchaeologist at University College London and the author of 'Growing Up Human: The Evolution of Childhood'.

Presented by Ella Al-Shamahi Produced by Jo Impey

Image: Teenagers dance the twist around a radio cassette recorder in a street in the Harajuku district of Shibuya, Tokyo, Japan, 1978 (Photo by Keystone/Hulton Archive/Getty Images)