David Mitchell is joined by Lucy Porter, Frankie Boyle, Sally Phillips, and Neil Delamere as they lie on the subjects of dolls, philosophers, tennis, and laughter.

The Truths

Lucy Porter - Dolls

- Voodoo dolls can cause psychological damage. Found by Sally. Accidentally included by Lucy.

- One German doll, the Birthday Man, gave children bonus gifts on their birthdays. Found by Frankie.

- One of Barbie's past jobs has been presidential candidate. Found by Neil.

- There is no tradition of sticking pins into dolls to harm people in Voodoo. In Voodoo, dolls are used for healing purposes and to communicate with the dead. Successfully smuggled.

- Thomas Edison sold talking dolls with miniature gramophones inside them. Successfully smuggled.

- As a boy, Alexander Graham Bell made a talking doll. It spoke the word "Mama" by using a bellows to blow through the doll's windpipe. Successfully smuggled.

Neil Delamere - Laughter

- In 2002, PETA claimed that cows experience embarrassment when people laugh at them. Found by Sally.

- In Tanganyika, a thousand people fell victim to a laughter epidemic in 1962, leading to 14 school closures. It only infected pupils, not teachers. It took about two years for the epidemic to end. Found by Sally.

- If you tickle a rat every day, it will start laughing as soon as it sees you. Successfully smuggled.

- In the culture of the Navajo, when a baby laughs for the first time the person who made the baby laugh has to pay for a celebratory meal. Successfully smuggled.

- The optimum number of words in a joke is no fewer than 103. In 2001, psychologist Richard Wiseman created Laugh Lab, a web-based international experiment to find the world's funniest joke. Jokes were rated on a five-point scale, and the ideal joke contains 103 words. People from Ireland, the UK, Australia and New Zealand most enjoyed jokes involving wordplay, one example being: "1Doctor, I've got a strawberry stuck up my arse.' 'Don't worry, I've got some cream for that.'" Successfully smuggled.

Sally Phillips - Tennis

- The greatest ever tennis player was J. Edmond Barde, who was a real tennis champion for 33 years in a row, 1829-1862, eventually defeat at the age of 60 by England's Edmund Tompkins. Found by Neil.

- When Roger Federer was a welcome late entrant in the 2013 Swiss open, he was given a cow called Desiree in the opening ceremony. The Swiss also gave Federer a cow called Juliette after his first win at Wimbledon in 2003. Desiree was sold at auction and Juliette was slaughtered. Found by Neil.

- Art Larsen, once the No. 1 US tennis player back in the 1950s, relied on an invisible eagle to bring him luck, which he said was perched on his shoulder giving him tactical advice during play. Successfully smuggled.

- Maria Sharapova has her own sweet company called Sugarpova. Successfully smuggled.

- At the US Open, men's balls are fluffy which slows them down. At Wimbledon, men and women compete with the same regular duty balls. Successfully smuggled.

Frankie Boyle - Philosophers

- According to his biographer, stoicism founder Zeno of Citium was so mortified after falling and stubbing his toe in front of his students that he held his breath until he died. Found by Neil.

- Nearly a quarter of philosophers believe in zombies. In philosophy, a zombie is an imaginary human designed to illuminate problems about consciousness and it's relation to the physical world. Found by Sally.

- Jeremy Bentham had a pet cat which he called The Reverend Sir John Langbourne which he served macaroni noodles to. He also had a pet pig which he permitted to share his bed with, a young ass, and a colony of mice which ran up his legs. Found by Sally.

- Jean-Paul Sartre had an obsessive fear of crustaceans and other sea creatures. Successfully smuggled.

- Jeremy Bentham invented jogging. He would wake up at six and jog for two hours before starting work. Successfully smuggled.

Scores

- Frankie Boyle and Neil Delamere: 2 points
- Lucy Porter: -1 point
- Sally Phillips: -2 points