Dolphins have the last laugh
QUESTION Is it true that rats can laugh? Can any other animals do this?
In 1999, neuroscientists Jaak Panksepp and Jeffrey Burgdorf demonstrated that tickling rats causes them to emit a series of high-pitched giggles, similar to those they make during play. They concluded this was a rudimentary form of laughter.
Humans can hear noise in the 20 khz to 40 khz range. Rats make long calls at 22 khz when they are scared or angry, but make short ultrasonic screeches at 50 khz, out of the range of human hearing, when they interact or are given food.
This response is dramatically increased by tickling, especially their neck.
The behaviour is so similar to human laughter that it likely results from the same mechanisms in the brain.
Rats are not the only laughing creatures. Marine researchers in Sweden believe they have recorded laughter in bottlenose dolphins. When play-fighting, dolphins emit a specific noise that indicate their intentions are non-threatening.
This occurs only during playful interactions and not during actual fights, leading researchers to believe it is a sort of chuckle that signals knockabout fun.
The great apes are our closest living relatives and share many similarities. Just like people, chimpanzees and bonobos are ticklish. When tickled in the armpits, neck or feet, they emit a shallow grunting sound that is believed to be a form of laughter.
Socialisation and play are important for these animals and laughter may help them discover personal boundaries.
Dr Ian Smith, Cambridge.
QUESTION Is it true that, when he was a child, comedian Bob Mortimer burnt his home down?
THIS is true. Bob revealed the story in a joking fashion on the BBC panel show Would I Lie To You? in 2017.
He gave much more detail in his moving appearance on Desert Island Discs in February when he highlighted the difficult situation it left his family in.
Mortimer was raised with his three brothers in the Linthorpe area of Middlesbrough. When he was seven, his father was killed in a car crash. It took him years to understand the effect this had on him.
For most of his life, he suffered from crippling shyness and an over-eagerness to please, which he believes stemmed from a fear of being abandoned. He described how he was his mother’s little helper and spent much of his youth vacuum-cleaning the house.
Speaking to Lauren Laverne on BBC Radio 4’s Desert Island Discs, he described that he was counting sparklers when he misinterpreted the warning on the packet that they were not suitable for indoor use and decided to set them alight in the house.
‘The sparklers lit the box of fireworks and I ran the box through to the kitchen and let them go off,’ he said.
‘I then spent about an hour trying to get rid of all the marks out of the lino and off cabinets. I walked back into the living room and it was fully ablaze.
‘I walked round to the two old ladies who lived next door and I said: “My house is on fire!” And they said: “You know, we thought it was.” ’
The family had to live apart and was crippled financially after the fire, yet they did not hold a grudge. Bob remained close to his brothers and spoke movingly about his mother, who worked for the Ministry of Food.
Brian Ash, Stoke-on-Trent, Staffs.