It often seems that life is more fun when you're young. And there's a scientific explanation for this - an experiment involving teenager Matt reveals why young people really do have more fun than adults. Matt's story is featured in Child of Our Time at 21:00 on Monday 3 April on BBC One. The second episode is at the same time on Tuesday 4 April. You can also catch up later online.
Looking back, a nine-year-old kid with a cherubic face, a natural gift for public speaking, and a one-million tree-planting challenge was irresistible to the world's media. Word of Finkbeiner's project spread rapidly. The next thing he knew, he was speaking to the European Parliament and attending UN conferences in Norway and South Korea. By the time he delivered his speech at the UN in New York in 2011, at the age of 13, Germany had planted its millionth tree, and Plant-for-the-Planet had been officially launched. It had a website and a full-time employee.
A 15-year-old girl has been found guilty of murdering a mother and daughter who were killed as they slept. Elizabeth Edwards and her 13-year-old daughter Katie were killed in Spalding, Lincolnshire in 2015. The teenager, who cannot be named because of her age, had denied the murders due to diminished responsibility. Her boyfriend - also aged 15 - had already admitted the killings. The teenagers are thought to be Britain's youngest ever couple to be convicted of murder.