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 8 - Changing Our Environment - Xand convinces Chris to come into his pottery shed and give it a whirl. Working together has historically resulted in heated arguments, so it’s time for Chris to act on what he’s learnt about improving his relationship with Xand. The twins consider how easy it is to roll out change on a large scale and ask Will Norman how he manages to implement change in the face of opposition. 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

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 7 - Changing in a Crisis - the twins speak with Louise, a social worker who supports people every day to make changes in their lives. Chris wants to know how people facing significant obstacles can make positive and successful changes. Louise’s experience prompts Chris to consider the way he approaches improving his relationship with Xand as well as how he advises his own patients. 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

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 6 - How To Listen To Your Body - Professor Sarah Garfinkel teaches the twins about interoception - or how we understand and act on what’s going on inside our bodies. She tests their ability to interpret their emotions and both Chris and Xand are surprised at the results. 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

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 5 - Learning To Listen - Chris considers the triggers for his many arguments with Xand and wonders if it might be because he’s not being a good listener. The psychotherapist Erene Hadjiioannou offers Chris some advice on how to react in the heat of an argument. Xand meanwhile is cocooned in his pottery shed contemplating Chris’ complete disinterest in his hobby. He wonders why everyone else in the family shows some enthusiasm, except his twin.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

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 4 - Does Willpower Even Exist? - Chris examines the slippery concept of willpower. Is it something that we all need in order to make personal change and if so, can Chris harness it to encourage Xand to make changes in their relationship? Xand is preoccupied with his exercise bike which stands unused and dusty in his house, can he find the motivation to use it? The psychologist and psychoanalyst Dr Stephen Blumenthal explains willpower in the brain - when does and doesn’t it work?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

Drs Chris and Xand discuss changing personalities and relationships. The twins explore nature vs nurture debate with psychologist Wendy Johnson. They reflect on personal growth, stress management, and willpower. Can they navigate complex relationships and resist change for the better?

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 2 - Does Our Birth Order Affect Our Personality? - the twins find out whether the order in which we’re born has any bearing on our personality. They call their little brother J who lives in New York and reminisce about their childhood. Chris’ wife Dinah and her older sisters debate whether showing off is the reserve of the youngest sibling. And psychologist Laura Botzet shares her findings from studies on the effect of birth order on personality. Does it have any credibility? 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

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 1 - The Twin Effect - Dr Clare Llewellyn explains why we should all care about twin studies and the importance of understanding the impact of genetics vs environment on our development. Chris and Xand meet identical twins Mia and Alexandra who were separated at birth. They reflect on their twin dynamic through the years - what has it meant for their development and can they change the dynamic they have now? 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

Drs Chris and Xand van Tulleken explore if people can change and how they do it. How much of our personality is genetic destiny and how much are we shaped by the world around us?A Loftus Media and van Tulleken Brothers Ltd production for BBC Radio 4

It’s been a year since Chris van Tulleken set his twin brother, Xand, a challenge to help him quit his addiction to junk food. Xand had to eat an 80% ultra-processed food (UPF) diet while learning about its health impact. It worked and by the end Xand rejected all those foods he’d previously adored, including his beloved Chinese dumplings. The experiment had an aversion effect, just as Chris had hoped. But something else happened during the experiment, Chris also had a conversion experience. A podcast about food addiction transformed into a podcast about the twins’ relationship and how best to help someone you love.In this episode, the twins reflect on their conversion experiences – are they eating better and more importantly, are they getting on better? Chris speaks to obesity expert Professor Rachel Batterham who tells him how the scientific discourse about UPF has developed since the end of series 1. And the twins go to see philosopher Barry Smith whose professional life has been affected by the twins’ experiment and he tells them why he’s now refusing to work with major food companies as a sensory consultant. When Xand pops round for tea one evening, Chris’s five-year-old daughter shares some home truths about her dad and uncle’s relationship and it prompts the twins to consider what else they need to improve in their lives. Presented by Drs Chris and Xand Van Tulleken Production team: Alexandra Quinn, Jo Rowntree, Hester Cant, Dan King and Maia Miller-Lewis A Loftus Media and van Tulleken Brothers Ltd production for BBC Radio 4.With thanks to Voltage TV for use of their archive.