Big School left me po-faced

How did our comedies become so sad? BBC1’s new sitcom Big School (Fridays) opened with a scene that would probably tickle the ribs of many, but I, in my usual humourless way, found it depressing. Chemistry teacher Mr Church, played by David Walliams, hoped to excite his morbidly uninterested pupils about the effects of dunking a bottle of cold liquid nitrogen in warm water by using hundreds of table-tennis balls to dramatise the resultant explosion. But the bell rang, and his students filed out of class radiating boredom and contempt, leaving Mr Church gazing forlornly at a thousand ping-ponging shells.

A similar sense of vulnerability permeated Boom Town, BBC3’s ‘structured reality’ series featuring a host of real-life eccentrics doing eccentric things in partly choreographed set pieces. (There’s a wannabe fashion designer, who tries to sell her dresses made of sanitary pads, a man who thinks he’s a witch, and so on.)