Most of us would like something about ourselves or our lives to be different, but how easy is it to actually change?

Drs Chris and Xand van Tulleken are looking at whether people can change and how they do it. Exactly how much of any aspect of personality is genetic destiny and how much are we shaped by the world around us?

Chris wants to be a better doctor, friend, husband and father. But most urgently he wants to be a better brother, and is determined to improve his relationship with Xand. They’re best friends and talk to each other every day, but they are also business partners who find it very hard to work together without having a visceral row.

Chris wants to change how he relates to his brother and believes it is possible, but Xand is less convinced that we can or that he needs to change. In this series, Chris confronts that pessimism.

In episode 3 - Nature via Nurture - the psychologist Wendy Johnson explodes some home truths around the great nature vs nurture debate. The twins speak to their younger brother J about some changes he’s been trying to implement in his own life that he hopes will improve the way he interacts with his kids. It leaves Chris wondering what he needs to exploit to continue trying to convince Xand to improve their relationship.

Presented by Drs Chris and Xand van Tulleken Produced by Hester Cant and Alexandra Quinn Series Editor: Jo Rowntree A Loftus Media and van Tulleken Brothers Ltd production for BBC Radio 4