of fingernails on blackboards and monkeys.

Why do we cringe at the sound of fingernails down a blackboard? Why do paper cuts hurt so much? Why do you sometimes bump into people on the pavement even though you can see them coming?

A new book by Laura Lee, The Pocket Encyclopaedia Of Aggravation, reveals the scientific facts behind life's most infuriating irritations. An article in The Mirror, gives us a preview.

Oh. And for those interested,

Fingernails: Researchers found a striking resemblance between the scraping and the warning cry of the macaque monkey. They now believe it may be an evolutionary reflex.

Paper cuts: The incisions may be small but they cut just into the layer of nerve endings. The paper also contains irritants - fibres and chemicals - which add to the pain

Bumping people: When nearing a stranger, you communicate which side you'll pass from 8ft away, by glancing to the left or right. Miss that signal and you may well collide.