Planet Child

Twin doctors Chris and Xand van Tulleken set out to explore whether the decline in children's freedom is affecting their ability to learn the skills they need for healthy development. We meet Michi, a seven year-old living in Tokyo who commutes across the city completely alone to get to school. Inspired by his independence, the van Tulleken's challenge a group of British children aged four-seven years old to travel across London and catch a bus to the London Eye - all without their parents.

Chris and Xand van Tulleken bring a group of children under the age of seven to London's Covent Garden to complete a series of temptation tests. Elsewhere, the pair set out to explore how we develop a sense of right and wrong and what makes one child well behaved and another naughty. Meanwhile, five-year-old Yorkshire farming cousins Kieron and Rita tussle over some abandoned money, and seven-year-old Alfie and twins Taiya and Tyiana agonise over what to do when they are left alone in a sweet shop.

In the third and final edition, twin doctors Chris and Xand van Tulleken set out to explore how children develop a sense of their own identity and whether girls are really different to boys. The van Tullekens take a group of British under-sevens away from their families to an island in the middle of the River Thames, to take part in experiments to find out what it means to be a girl or a boy. Twin sisters Tyiana and Taiya shock themselves and the boys in a fairground competition and four-year-old American pageant queen Lyndsey has very strong ideas about how she likes to look.