The Why Factor

Helena Merriman asks why people listen to sad music. A recent study has shown that sad music has become increasingly popular, but why do people choose to listen to it, and what goes on in the brain and the body when they do so? Helena speaks to Japanese pianist and music researcher Dr Ai Kawakami who has some surprising answers about some of the positive feelings people experience when they listen to sad music. American writer Amanda Stern tells Helena why she regularly listens (and cries) to sad music and British composer Debbie Wiseman, known for her moving TV and film scores, explains what makes a piece of music sound sad. You’ll also hear pieces of sad music suggested by BBC listeners from all over the world. (Photo: A woman with headphones on, listening to sad music. BBC Copyright)

Humans need to eat to survive. So why would someone go voluntarily without food - or even water? Many of the major religions observe periods of fasting for spiritual reasons. Charlotte McDonald speaks to those who have fasted to find out why they do it. Also, is there a place in modern society for fasting for non-religious reasons? She speaks to Michael Mosley about the science behind fasting and why some people are choosing it as a lifestyle choice.(Image: Indian Muslims offer prayers prior to breaking their fast on the first day of the holy fasting month of Ramadan. Credit: AFP/Getty Images)

Memory plays a big part in shaping our identity, but can we rely on what we recall about ourselves and about others? Mike Williams finds out how human memory works and why some memories flood back more easily than others. He also explores whether different senses trigger different types of memories. Mike speaks to memory experts Martin Conway, Elizabeth Loftus, Gisli Gudjonsson, Maria Larsson and Simon Chu. The reader is Roberto Pistolesi.(Photo: Image of a brain scan. Credit: AFP/Getty Images)

Why do so many women feel the need to get rid of their body hair? Why is it fine for a man to sport hairy legs, but unthinkable for most women? It’s a sensitive subject - touching on ideas about female sexuality and gender politics that stretch back almost to the beginning of time.(Image of an actress with her arms up in the air, posing for a portrait. Credit: Getty Images)

Around the world people have different rules for their relationships - rules often dictated by culture and religion. In many societies the most important of these is sexual fidelity - true love and monogamy are expected to go hand in hand - but why should love mean forsaking all others? And what happens to relationships when monogamy is cast adrift?(Image of couples kissing and celebrating the eve of Valentine's Day. Credit: Getty Images)

Why has the modern world become so obsessed with celebrity culture? Where does it come from? How do you achieve it? And how do you fake it? Mike Williams hears from Brett Cohen, a man who fabricated his own fame and became famous for not being famous. He also speaks to an academic who argues that evolution has left us foolishly following unsuitable celebrity role models. From the world's first celebrity to the pop-icons of today, why are they adored by millions and why are they so influential? It is easy to understand why you might want to buy football boots endorsed by David Beckham, but why would you want underwear which carries his name? Or a perfume endorsed by singer Beyonce. Or George Clooney's favourite coffee?(Image: Justin Bieber arriving at a music video awards ceremony in Toronto, Canada. Credit: Getty Images)

For the last few hundred years, humans have tried to scale ever more dangerous peaks. But why do they do it? Mike Williams travels to the Alps to find out. He speaks to skilled climbers including the son of American mountaineer John Harlin II, who died trying to scale the north face of the savage Eiger in Switzerland. Why do they take such risks and what do they get out of it?(Image: North Face of the Eiger Mountain in the Swiss Alps. BBC Copyright)

***Warning: This programme contains graphic descriptions of violence*** Why are we so drawn to violent entertainment? Violent films, video games and stories are very popular, as were brutal gladiatorial Roman contests and gory 14th Century jousts. What explains this enduring attraction to violence? Helena Merriman talks to the Mexican director of Heli, a professor of fairy tales and joins one of London’s most gruesome serial killer tours to answer this week’s question.(Image of Daniel Craig pointing a gun, as James Bond. Credit: Eon productions via Press Association)

Why are attitudes towards older people often so negative? Traditional definitions used to mark old age at around retirement - 60– 65 years. But with many of us expected to live well into our 80s and beyond, that now seems absurd. Mike Williams talks to the old and the young, and asks how might we re-think of this period of our lives ? (Image: A woman holds the hands of an elderly relative. Credit: AFP/Getty Images )

In this programme, Mike Williams asks why people have tattoos. Where do they come from and what do they say about us? From the Maori of New Zealand to the Mexican Mafia, Mike explores the universal motivation behind why people decorate their bodies with ink. (Image: David Beckham's tattooed bare back. Credit: AFP/Getty Images)