Clown doctors Calum MacAskill and Lucy McGreal and fellow performers Tim Licata and Suzie Ferguson help launch Scotland's Big Laugh, a campaign to highlight the importance of laughter that is backed by the Scottish Liberal Democrat leader Willie Rennie.

The MSP has teamed up with research scientist Suzanne Zeedyk and an organisation that helps toddlers get creative to launch the event, which follows on from last year's Silly Moments. Ms Zeedyk said: " Big Laugh is all about fostering a deeper appreciation of our desperate need of laughter, in both our personal lives and in our society."

Mr Rennie MSP is sponsoring the campaign at the Scottish Parliament.

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